Add multi-variant support to the app

2026-09-29 20:01:26 +00:00 · 2026-09-28 19:08:35 +08:00
parent 2ccabb5695
commit 71bb400e46
27 changed files with 846 additions and 195 deletions
@@ -199,7 +199,8 @@ DynamicPrintConfig PresetBundle::construct_full_config(
    if (num_filaments <= 1) {
        // BBS: update filament config related with variants
        DynamicPrintConfig filament_config = in_filament_presets[0].config;
-        if (apply_extruder && ((extruder_count > 1) || different_extruder))
+        // Orca: a multi-variant filament resolves its variants on a single-variant printer too.
+        if (apply_extruder && ((extruder_count > 1) || different_extruder || filament_config.has_multi_variant_filament()))
            filament_config.update_values_to_printer_extruders(out, extruder_count, extruder_volume_type_count, nozzle_volume_types, filament_options_with_variant, "", "filament_extruder_variant", 1, filament_maps[0], (NozzleVolumeType)filament_volume_maps[0]);
        out.apply(filament_config);
        compatible_printers_condition.emplace_back(in_filament_presets[0].compatible_printers_condition());
@@ -223,7 +224,8 @@ DynamicPrintConfig PresetBundle::construct_full_config(
        filament_temp_configs.resize(num_filaments);
        for (size_t i = 0; i < num_filaments; ++i) {
            filament_temp_configs[i] = *(filament_configs[i]);
-            if (apply_extruder && ((extruder_count > 1) || different_extruder))
+            // Orca: a multi-variant filament resolves its variants on a single-variant printer too.
+            if (apply_extruder && ((extruder_count > 1) || different_extruder || filament_temp_configs[i].has_multi_variant_filament()))
                filament_temp_configs[i].update_values_to_printer_extruders(out, extruder_count, extruder_volume_type_count, nozzle_volume_types, filament_options_with_variant, "", "filament_extruder_variant", 1, filament_maps[i], (NozzleVolumeType)filament_volume_maps[i]);
        }

@@ -4664,7 +4666,8 @@ DynamicPrintConfig PresetBundle::full_fff_config(bool apply_extruder, std::optio
    if (num_filaments <= 1) {
        //BBS: update filament config related with variants
        DynamicPrintConfig filament_config = this->filaments.get_edited_preset().config;
-        if (apply_extruder && ((extruder_count > 1) || different_extruder))
+        // Orca: a multi-variant filament resolves its variants on a single-variant printer too.
+        if (apply_extruder && ((extruder_count > 1) || different_extruder || filament_config.has_multi_variant_filament()))
            filament_config.update_values_to_printer_extruders(out, extruder_count, extruder_volume_type_count, nozzle_volume_types, filament_options_with_variant, "", "filament_extruder_variant", 1, filament_maps[0], (NozzleVolumeType)filament_volume_maps[0]);
        out.apply(filament_config);
        compatible_printers_condition.emplace_back(this->filaments.get_edited_preset().compatible_printers_condition());
@@ -4758,7 +4761,8 @@ DynamicPrintConfig PresetBundle::full_fff_config(bool apply_extruder, std::optio
        filament_temp_configs.resize(num_filaments);
        for (size_t i = 0; i < num_filaments; ++i) {
            filament_temp_configs[i] = *(filament_configs[i]);
-            if (apply_extruder && ((extruder_count > 1) || different_extruder))
+            // Orca: a multi-variant filament resolves its variants on a single-variant printer too.
+            if (apply_extruder && ((extruder_count > 1) || different_extruder || filament_temp_configs[i].has_multi_variant_filament()))
                filament_temp_configs[i].update_values_to_printer_extruders(out, extruder_count, extruder_volume_type_count, nozzle_volume_types, filament_options_with_variant, "", "filament_extruder_variant", 1, filament_maps[i], (NozzleVolumeType)filament_volume_maps[i]);
        }

@@ -3938,6 +3938,9 @@ void Print::update_filament_maps_to_config(std::vector<int> f_maps, std::vector<
    {
        int extruder_count = 1, extruder_volume_type_count = 1;
        bool support_multi = m_ori_full_print_config.support_different_extruders(extruder_count);
+        // Orca: resolve the filament variants wherever Print::apply does, a multi-variant filament
+        // on a single-variant printer included.
+        const bool expand_filaments = (extruder_count > 1) || support_multi || m_ori_full_print_config.has_multi_variant_filament();
        std::vector<std::vector<NozzleVolumeType>> nozzle_volume_types;
        extruder_volume_type_count = m_ori_full_print_config.get_extruder_nozzle_volume_count(extruder_count, nozzle_volume_types);

@@ -3978,7 +3981,7 @@ void Print::update_filament_maps_to_config(std::vector<int> f_maps, std::vector<
        m_full_print_config = m_ori_full_print_config;
        std::set<std::string> filament_keys = filament_options_with_variant;
        filament_keys.insert("filament_self_index");
-        if ((extruder_count > 1) || support_multi)
+        if (expand_filaments)
            m_full_print_config.update_values_to_printer_extruders_for_multiple_filaments(m_full_print_config, extruder_count, extruder_volume_type_count, filament_keys,  "filament_self_index", "filament_extruder_variant");

        const std::vector<std::string> &extruder_retract_keys = print_config_def.extruder_retract_keys();
@@ -3995,7 +3998,7 @@ void Print::update_filament_maps_to_config(std::vector<int> f_maps, std::vector<
                compute_filament_override_value(opt_key, opt_old_machine, opt_new_machine, opt_new_filament, m_full_print_config, print_diff, filament_overrides, m_config.filament_map_2.values);
        }

-        if ((extruder_count > 1) || support_multi) {
+        if (expand_filaments) {
            t_config_option_keys keys(filament_options_with_variant.begin(), filament_options_with_variant.end());
            keys.push_back("filament_self_index");
            m_config.apply_only(m_full_print_config, keys, true);
@@ -1296,7 +1296,9 @@ Print::ApplyStatus Print::apply(const Model &model, DynamicPrintConfig new_full_
                                                                                 extruder_count, extruder_volume_type_count, filament_keys,
                                                                                 "filament_self_index", "filament_extruder_variant",
                                                                                 &dynamic_slot_indices);
-        else if ((extruder_count > 1) || different_extruder)
+        // Orca: also on a printer with a single extruder variant once a filament defines several
+        // (e.g. Standard and High Flow), so each filament takes its variant for that extruder.
+        else if ((extruder_count > 1) || different_extruder || new_full_config.has_multi_variant_filament())
            new_full_config.update_values_to_printer_extruders_for_multiple_filaments(m_ori_full_print_config, extruder_count, extruder_volume_type_count, filament_keys,
                                                                                      "filament_self_index", "filament_extruder_variant");
    }
@@ -626,7 +626,8 @@ static const t_config_enum_values s_keys_map_NozzleVolumeType = {
    { "Standard",  nvtStandard },
    { "High Flow", nvtHighFlow },
    { "TPU High Flow", nvtTPUHighFlow },
-    { "Hybrid", nvtHybrid }
+    { "Hybrid", nvtHybrid },
+    { "E3D High Flow", nvtE3DHighFlow }
 };
 CONFIG_OPTION_ENUM_DEFINE_STATIC_MAPS(NozzleVolumeType)

@@ -676,9 +677,34 @@ int get_config_index_base(NozzleVolumeType volume_type, ExtruderType extruder_ty
    for (int index = 0; index < int(variant_list.size()); ++index) {
        if (extruder_variant == variant_list[index] && variant_ids_1based[index] == variant_id_1based) { return index; }
    }
+    // Without this variant, use the id's own first variant (usually Standard), not variant index 0,
+    // which belongs to the first filament or extruder.
+    for (int index = 0; index < int(variant_list.size()); ++index) {
+        if (variant_ids_1based[index] == variant_id_1based) { return index; }
+    }
    return 0;
 }

+std::set<NozzleVolumeType> get_extruder_supported_nozzle_volume_types(const DynamicPrintConfig &printer_config, int extruder_id)
+{
+    std::set<NozzleVolumeType> supported_types;
+
+    auto *variant_list   = printer_config.option<ConfigOptionStrings>("extruder_variant_list");
+    auto *extruder_types = printer_config.option<ConfigOptionEnumsGeneric>("extruder_type");
+    if (!variant_list || !extruder_types || extruder_id < 0 ||
+        extruder_id >= (int) variant_list->values.size() || extruder_id >= (int) extruder_types->values.size())
+        return supported_types;
+
+    const ExtruderType extruder_type = ExtruderType(extruder_types->values[extruder_id]);
+    for (NozzleVolumeType volume_type : get_valid_nozzle_volume_type()) {
+        // An unsupported extruder type yields an empty name, which would match any list.
+        const std::string variant = get_extruder_variant_string(extruder_type, volume_type);
+        if (!variant.empty() && variant_list->values[extruder_id].find(variant) != std::string::npos)
+            supported_types.insert(volume_type);
+    }
+    return supported_types;
+}
+
 std::string get_nozzle_volume_type_string(NozzleVolumeType nozzle_volume_type)
 {
    if (nozzle_volume_type > nvtMaxNozzleVolumeType) {
@@ -5923,15 +5949,18 @@ void PrintConfigDef::init_fff_params()
    def->label = "Nozzle Volume Type";
    def->tooltip = "Nozzle volume type for extruders.";
    def->enum_keys_map = &ConfigOptionEnum<NozzleVolumeType>::get_enum_values();
-    // Order must match the NozzleVolumeType enum values (Standard=0, High Flow=1, Hybrid=2, TPU High Flow=3).
+    // Listed in display order. A position is not the enum value (E3D High Flow is 5, after the reserved 4),
+    // so map a position to its NozzleVolumeType through enum_keys_map.
    def->enum_values.push_back(L("Standard"));
    def->enum_values.push_back(L("High Flow"));
    def->enum_values.push_back(L("Hybrid"));
    def->enum_values.push_back(L("TPU High Flow"));
+    def->enum_values.push_back(L("E3D High Flow"));
    def->enum_labels.push_back(L("Standard"));
    def->enum_labels.push_back(L("High Flow"));
    def->enum_labels.push_back(L("Hybrid"));
    def->enum_labels.push_back(L("TPU High Flow"));
+    def->enum_labels.push_back(L("E3D High Flow"));
    def->mode = comSimple;
    def->set_default_value(new ConfigOptionEnumsGeneric{ NozzleVolumeType::nvtStandard });

@@ -5944,10 +5973,12 @@ void PrintConfigDef::init_fff_params()
    def->enum_values.push_back(L("High Flow"));
    def->enum_values.push_back(L("Hybrid"));
    def->enum_values.push_back(L("TPU High Flow"));
+    def->enum_values.push_back(L("E3D High Flow"));
    def->enum_labels.push_back(L("Standard"));
    def->enum_labels.push_back(L("High Flow"));
    def->enum_labels.push_back(L("Hybrid"));
    def->enum_labels.push_back(L("TPU High Flow"));
+    def->enum_labels.push_back(L("E3D High Flow"));
    def->mode = comDevelop;
    def->set_default_value(new ConfigOptionEnumsGeneric{ NozzleVolumeType::nvtStandard });

@@ -5986,7 +6017,7 @@ void PrintConfigDef::init_fff_params()
    // Per-nozzle volume type. Forward-compat-only registration with no slicing consumer — nothing in
    // src/ reads it; the engine resolves per-nozzle volume types from `extruder_nozzle_stats` tokens
    // instead. Kept registered so a project/config carrying it loads without an unknown-option
-    // substitution warning. Registers Standard/High Flow/TPU High Flow only (no Hybrid).
+    // substitution warning. Registers the physical types only (no Hybrid).
    // Internal use only, no translation.
    def = this->add("extruder_nozzle_volume_type", coEnums);
    def->label = "Extruder nozzle volume type";
@@ -5995,9 +6026,11 @@ void PrintConfigDef::init_fff_params()
    def->enum_values.push_back("Standard");
    def->enum_values.push_back("High Flow");
    def->enum_values.push_back("TPU High Flow");
+    def->enum_values.push_back("E3D High Flow");
    def->enum_labels.push_back("Standard");
    def->enum_labels.push_back("High Flow");
    def->enum_labels.push_back("TPU High Flow");
+    def->enum_labels.push_back("E3D High Flow");
    def->mode = comDevelop;
    def->set_default_value(new ConfigOptionEnumsGeneric{ NozzleVolumeType::nvtStandard });

@@ -10070,6 +10103,13 @@ bool DynamicPrintConfig::is_using_different_extruders()
    return ret;
 }

+bool DynamicPrintConfig::has_multi_variant_filament() const
+{
+    auto variants  = dynamic_cast<const ConfigOptionStrings*>(this->option("filament_extruder_variant"));
+    auto diameters = dynamic_cast<const ConfigOptionFloats*>(this->option("filament_diameter"));
+    return variants && diameters && variants->size() > diameters->size();
+}
+
 bool DynamicPrintConfig::support_different_extruders(int& extruder_count) const
 {
    std::set<std::string> variant_set;
@@ -11070,6 +11110,11 @@ void DynamicPrintConfig::update_values_to_printer_extruders_for_multiple_filamen
            return;
        }
        std::vector<int> filament_maps = opt_filament_map->values;
+        auto opt_ids = id_name.empty()? nullptr: dynamic_cast<const ConfigOptionInts*>(this->option(id_name));
+        // Orca: a map shorter than the filament count must not drop the filaments past its end;
+        // they take the first extruder.
+        if (opt_ids && !opt_ids->values.empty())
+            filament_maps.resize(std::max<size_t>(filament_maps.size(), *std::max_element(opt_ids->values.begin(), opt_ids->values.end())), 1);
        size_t filament_count = filament_maps.size();
        //apply process settings
        auto opt_extruder_type = dynamic_cast<const ConfigOptionEnumsGeneric*>(printer_config.option("extruder_type"));
@@ -11088,7 +11133,6 @@ void DynamicPrintConfig::update_values_to_printer_extruders_for_multiple_filamen
        // indexed out of bounds.
        if (opt_filament_volume_maps && opt_filament_volume_maps->values.size() == filament_count)
            filament_volume_maps = opt_filament_volume_maps->values;
-        auto opt_ids = id_name.empty()? nullptr: dynamic_cast<const ConfigOptionInts*>(this->option(id_name));
        std::vector<int> variant_index;

        variant_index.resize(filament_count, -1);
@@ -11105,9 +11149,10 @@ void DynamicPrintConfig::update_values_to_printer_extruders_for_multiple_filamen
            //variant index
            variant_index[f_index] = get_index_for_extruder(f_index+1, id_name, extruder_type, nozzle_volume_type, variant_name);
            if (variant_index[f_index] < 0) {
-                BOOST_LOG_TRIVIAL(error) << __FUNCTION__ << boost::format(", Line %1%: could not found extruder_type %2%, nozzle_volume_type %3%, filament_index %4%, extruder index %5%")
+                // Orca: a filament need not define every extruder variant (a Direct Drive filament on a
+                // Bowden printer), so this is not an invalid state: the filament's first variant is used.
+                BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << boost::format(", Line %1%: could not found extruder_type %2%, nozzle_volume_type %3%, filament_index %4%, extruder index %5%")
                    %__LINE__ %s_keys_names_ExtruderType[extruder_type] % s_keys_names_NozzleVolumeType[nozzle_volume_type] % (f_index+1) %filament_maps[f_index];
-                assert(false);
                //for some updates happens in a invalid state(caused by popup window)
                //we need to avoid crash
                variant_index[f_index] = 0;
@@ -30,6 +30,8 @@

 namespace Slic3r {

+class DynamicPrintConfig;
+
 enum GCodeFlavor : unsigned char {
    gcfMarlinLegacy, 
    gcfKlipper, 
@@ -519,8 +521,10 @@ enum NozzleVolumeType {
                     // with more than one sub-nozzle (extruder_max_nozzle_count > 1); matched as Standard for
                     // preset lookup and never emitted in profile variant strings
    nvtTPUHighFlow,  // physical variant, used on H2D/H2DP 0.4 nozzles only
+    // 4 is reserved: E3D High Flow is 5 in BambuStudio's slice_info and device numbering.
+    nvtE3DHighFlow = 5, // physical variant, E3D high-flow hotend on 0.4/0.6 nozzles
    // Integer values are serialized as raw ints in 3mf plate metadata and device MQTT, so they MUST stay stable.
-    nvtMaxNozzleVolumeType = nvtTPUHighFlow
+    nvtMaxNozzleVolumeType = nvtE3DHighFlow
 };

 enum FilamentMapMode {
@@ -558,11 +562,19 @@ static std::set<NozzleVolumeType> get_valid_nozzle_volume_type() {
        // Hybrid is not a physical nozzle variant: presets never define it, so it must not
        // produce a variant string.
        if (t == nvtHybrid) continue;
+        // Skip the reserved gap between nvtTPUHighFlow (3) and nvtE3DHighFlow (5).
+        if (i > nvtTPUHighFlow && i < nvtE3DHighFlow) continue;
        type.insert(t);
    }
    return type;
 }

+// The nozzle volume types the given extruder physically provides, as declared by the printer
+// profile's extruder_variant_list. An empty set means the profile could not be read and must be
+// treated as "unknown", not as "none". nvtHybrid is never reported: it describes an extruder
+// holding a mix of nozzles, not a nozzle the profile can offer.
+extern std::set<NozzleVolumeType> get_extruder_supported_nozzle_volume_types(const DynamicPrintConfig &printer_config, int extruder_id);
+
 std::string get_nozzle_volume_type_string(NozzleVolumeType nozzle_volume_type);

 static std::string bed_type_to_gcode_string(const BedType type)
@@ -699,8 +711,6 @@ CONFIG_OPTION_ENUM_DECLARE_STATIC_MAPS(SurfaceFillOrder)

 #undef CONFIG_OPTION_ENUM_DECLARE_STATIC_MAPS

-class DynamicPrintConfig;
-
 // Defines each and every configuration option of Slic3r, including the properties of the GUI dialogs.
 // Does not store the actual values, but defines default values.
 class PrintConfigDef : public ConfigDef
@@ -821,6 +831,10 @@ public:
    //BBS
    bool is_using_different_extruders();
    bool support_different_extruders(int& extruder_count) const;
+    // Whether any filament defines more than one variant (filament_extruder_variant longer than
+    // filament_diameter). Its variants then have to be resolved even on a printer with a single
+    // extruder variant, which picks the filament's variant of the same variant string.
+    bool has_multi_variant_filament() const;
    // Counts the config slots of a printer: one per (extruder x nozzle volume type) as described by
    // extruder_nozzle_stats, or simply one per extruder when the stats are absent/mismatched.
    // Fills nozzle_volume_types with each extruder's volume types in ascending enum order.
@@ -818,12 +818,14 @@ NewCalibrationHistoryDialog::NewCalibrationHistoryDialog(wxWindow *parent, const
    if (support_nozzle_volume(curr_obj)) {
        Label *nozzle_name_title = new Label(top_panel, _L("Nozzle"));
        m_comboBox_nozzle_type   = new ::ComboBox(top_panel, wxID_ANY, wxEmptyString, wxDefaultPosition, NEW_HISTORY_DIALOG_INPUT_SIZE, 0, nullptr, wxCB_READONLY);
-        wxArrayString          nozzle_items;
+        // The labels are in display order, not enum order (E3D High Flow is 5 but the fifth label), so each
+        // item carries its NozzleVolumeType as client data.
        const ConfigOptionDef *nozzle_volume_type_def = print_config_def.get("nozzle_volume_type");
        if (nozzle_volume_type_def && nozzle_volume_type_def->enum_keys_map) {
-            for (auto item : nozzle_volume_type_def->enum_labels) { nozzle_items.push_back(_L(item)); }
+            for (size_t i = 0; i < nozzle_volume_type_def->enum_labels.size(); ++i)
+                m_comboBox_nozzle_type->Append(_L(nozzle_volume_type_def->enum_labels[i]), wxNullBitmap,
+                                               (void *) (intptr_t) nozzle_volume_type_def->enum_keys_map->at(nozzle_volume_type_def->enum_values[i]));
        }
-        m_comboBox_nozzle_type->Set(nozzle_items);
        m_comboBox_nozzle_type->SetSelection(-1);
        flex_sizer->Add(nozzle_name_title);
        flex_sizer->Add(m_comboBox_nozzle_type);
@@ -891,7 +893,7 @@ int NewCalibrationHistoryDialog::get_nozzle_combo_id_code() const

 void NewCalibrationHistoryDialog::on_select_nozzle_pos(wxCommandEvent &event)
 {
-    // Mirror the picked hotend's flow onto the (Orca index-based) nozzle-type combo.
+    // Mirror the picked hotend's flow onto the nozzle-type combo.
    if (!curr_obj || !m_comboBox_nozzle_id || !m_comboBox_nozzle_type || !curr_obj->GetNozzleSystem())
        return;

@@ -902,7 +904,9 @@ void NewCalibrationHistoryDialog::on_select_nozzle_pos(wxCommandEvent &event)
    DevNozzle nozzle = curr_obj->GetNozzleSystem()->GetNozzleByPosId(pos);
    if (nozzle.IsNormal()) {
        NozzleVolumeType volume_type = DevNozzle::ToNozzleVolumeType(nozzle.GetNozzleFlowType());
-        m_comboBox_nozzle_type->SetSelection(static_cast<int>(volume_type));
+        for (unsigned int i = 0; i < m_comboBox_nozzle_type->GetCount(); ++i)
+            if (NozzleVolumeType(intptr_t(m_comboBox_nozzle_type->GetClientData(i))) == volume_type)
+                m_comboBox_nozzle_type->SetSelection(i);
    }
 }

@@ -949,7 +953,7 @@ void NewCalibrationHistoryDialog::on_ok(wxCommandEvent &event)
            msg_dlg.ShowModal();
            return;
        }
-        m_new_result.nozzle_volume_type = NozzleVolumeType(m_comboBox_nozzle_type->GetSelection());
+        m_new_result.nozzle_volume_type = NozzleVolumeType(intptr_t(m_comboBox_nozzle_type->GetClientData(m_comboBox_nozzle_type->GetSelection())));
    }

    auto filament_item = map_filament_items[m_comboBox_filament->GetValue().ToStdString()];
@@ -803,6 +803,29 @@ void CalibrationPresetPage::create_selection_panel(wxWindow* parent)
 #define NOZZLE_LIST_DEFAULT     1
 float nozzle_diameter_list[NOZZLE_LIST_COUNT] = {0.2, 0.4, 0.6, 0.8 };

+// The nozzle_volume_type labels are in display order, not enum order (E3D High Flow is 5 but the fifth
+// label), so each item carries its NozzleVolumeType as client data and is selected by that value.
+static void select_nozzle_volume(ComboBox *combo, NozzleVolumeType volume_type)
+{
+    for (unsigned int i = 0; i < combo->GetCount(); ++i)
+        if (NozzleVolumeType(intptr_t(combo->GetClientData(i))) == volume_type) {
+            combo->SetSelection(i);
+            return;
+        }
+}
+
+static void fill_nozzle_volume_combo(ComboBox *combo)
+{
+    combo->Clear();
+    const ConfigOptionDef *nozzle_volume_type_def = print_config_def.get("nozzle_volume_type");
+    if (nozzle_volume_type_def && nozzle_volume_type_def->enum_keys_map) {
+        for (size_t i = 0; i < nozzle_volume_type_def->enum_labels.size(); ++i)
+            combo->Append(_L(nozzle_volume_type_def->enum_labels[i]), wxNullBitmap,
+                          (void *) (intptr_t) nozzle_volume_type_def->enum_keys_map->at(nozzle_volume_type_def->enum_values[i]));
+    }
+    select_nozzle_volume(combo, NozzleVolumeType::nvtStandard);
+}
+
 void CalibrationPresetPage::init_selection_values()
 {
    // init nozzle diameter and nozzle volume
@@ -813,15 +836,7 @@ void CalibrationPresetPage::init_selection_values()
        }
        m_comboBox_nozzle_dia->SetSelection(NOZZLE_LIST_DEFAULT);

-        m_comboBox_nozzle_volume->Clear();
-        const ConfigOptionDef *nozzle_volume_type_def = print_config_def.get("nozzle_volume_type");
-        if (nozzle_volume_type_def && nozzle_volume_type_def->enum_keys_map) {
-            for (auto item : nozzle_volume_type_def->enum_labels) {
-                m_comboBox_nozzle_volume->AppendString(_L(item));
-            }
-        }
-
-        m_comboBox_nozzle_volume->SetSelection(int(NozzleVolumeType::nvtStandard));
+        fill_nozzle_volume_combo(m_comboBox_nozzle_volume);
    }

    Preset* cur_printer_preset = get_printer_preset(curr_obj, 0.4);
@@ -866,15 +881,7 @@ void CalibrationPresetPage::init_selection_values()
        }
        m_left_comboBox_nozzle_dia->SetSelection(NOZZLE_LIST_DEFAULT);

-        m_left_comboBox_nozzle_volume->Clear();
-        const ConfigOptionDef *nozzle_volume_type_def = print_config_def.get("nozzle_volume_type");
-        if (nozzle_volume_type_def && nozzle_volume_type_def->enum_keys_map) {
-            for (auto item : nozzle_volume_type_def->enum_labels) {
-                m_left_comboBox_nozzle_volume->AppendString(_L(item));
-            }
-        }
-
-        m_left_comboBox_nozzle_volume->SetSelection(int(NozzleVolumeType::nvtStandard));
+        fill_nozzle_volume_combo(m_left_comboBox_nozzle_volume);
    }

    // right
@@ -885,15 +892,7 @@ void CalibrationPresetPage::init_selection_values()
        }
        m_right_comboBox_nozzle_dia->SetSelection(NOZZLE_LIST_DEFAULT);

-        m_right_comboBox_nozzle_volume->Clear();
-        const ConfigOptionDef *nozzle_volume_type_def = print_config_def.get("nozzle_volume_type");
-        if (nozzle_volume_type_def && nozzle_volume_type_def->enum_keys_map) {
-            for (auto item : nozzle_volume_type_def->enum_labels) {
-                m_right_comboBox_nozzle_volume->AppendString(_L(item));
-            }
-        }
-
-        m_right_comboBox_nozzle_volume->SetSelection(int(NozzleVolumeType::nvtStandard));
+        fill_nozzle_volume_combo(m_right_comboBox_nozzle_volume);
    }
 }

@@ -980,13 +979,13 @@ NozzleVolumeType CalibrationPresetPage::get_nozzle_volume_type(int extruder_id)
    if (curr_obj) {
        if (curr_obj->is_multi_extruders()) {
            if (extruder_id == LEFT_EXTRUDER_ID) {
-                return NozzleVolumeType(m_left_comboBox_nozzle_volume->GetSelection());
+                return NozzleVolumeType(intptr_t(m_left_comboBox_nozzle_volume->GetClientData(m_left_comboBox_nozzle_volume->GetSelection())));
            } else if (extruder_id == RIGHT_EXTRUDER_ID) {
-                return NozzleVolumeType(m_right_comboBox_nozzle_volume->GetSelection());
+                return NozzleVolumeType(intptr_t(m_right_comboBox_nozzle_volume->GetClientData(m_right_comboBox_nozzle_volume->GetSelection())));
            }
        }
        else
-            return NozzleVolumeType(m_comboBox_nozzle_volume->GetSelection());
+            return NozzleVolumeType(intptr_t(m_comboBox_nozzle_volume->GetClientData(m_comboBox_nozzle_volume->GetSelection())));
    }
    return NozzleVolumeType::nvtStandard;
 }
@@ -2139,7 +2138,7 @@ void CalibrationPresetPage::init_with_machine(MachineObject* obj)
                }

                if (obj->GetExtderSystem()->GetNozzleFlowType(i) != NozzleFlowType::NONE_FLOWTYPE) {
-                    m_left_comboBox_nozzle_volume->SetSelection(int(DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(i))));
+                    select_nozzle_volume(m_left_comboBox_nozzle_volume, DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(i)));
                } else {
                    m_left_comboBox_nozzle_volume->SetSelection(0);
                }
@@ -2159,7 +2158,7 @@ void CalibrationPresetPage::init_with_machine(MachineObject* obj)
                }

                if (obj->GetExtderSystem()->GetNozzleFlowType(i) != NozzleFlowType::NONE_FLOWTYPE) {
-                    m_right_comboBox_nozzle_volume->SetSelection(int(DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(i))));
+                    select_nozzle_volume(m_right_comboBox_nozzle_volume, DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(i)));
                } else {
                    m_right_comboBox_nozzle_volume->SetSelection(0);
                }
@@ -2197,7 +2196,7 @@ void CalibrationPresetPage::init_with_machine(MachineObject* obj)
    else {
        if ((obj->GetExtderSystem()->GetTotalExtderCount() > 0) && (obj->GetExtderSystem()->GetNozzleFlowType(0) != NozzleFlowType::NONE_FLOWTYPE))
        {
-            m_comboBox_nozzle_volume->SetSelection(int(DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(0))));
+            select_nozzle_volume(m_comboBox_nozzle_volume, DevNozzle::ToNozzleVolumeType(obj->GetExtderSystem()->GetNozzleFlowType(0)));
        } else {
            m_comboBox_nozzle_volume->SetSelection(0);
        }
@@ -732,6 +732,7 @@ void CaliPASaveAutoPanel::sync_cali_result_for_multi_extruder(const std::vector<
                case NozzleVolumeType::nvtStandard:    nozzle_id_str += _L("Standard Flow"); break;
                case NozzleVolumeType::nvtHighFlow:    nozzle_id_str += _L("High Flow"); break;
                case NozzleVolumeType::nvtTPUHighFlow: nozzle_id_str += _L("TPU High Flow"); break;
+                case NozzleVolumeType::nvtE3DHighFlow: nozzle_id_str += _L("E3D High Flow"); break;
                default: break;
                }
                nozzle_id_value->SetLabel(nozzle_id_str);
@@ -36,7 +36,8 @@ static NozzleVolumeType convert_to_nozzle_type(const std::string &str)
        return NozzleVolumeType::nvtHighFlow;
    else if (str[1] == 'U')
        return NozzleVolumeType::nvtTPUHighFlow;
-    // Orca: no nvtE3DHighFlow in Orca's NozzleVolumeType; map 'B' to Standard
+    else if (str[1] == 'B')
+        return NozzleVolumeType::nvtE3DHighFlow;
    else
        return NozzleVolumeType::nvtStandard;
 }
@@ -13,7 +13,7 @@
 namespace Slic3r
 {

-// ---- DevNozzle: flow/volume conversions (Standard / High Flow / TPU High Flow) ----------------------
+// ---- DevNozzle: flow/volume conversions (Standard / High Flow / TPU High Flow / E3D High Flow) ------
 // Device-reported U_FLOW nozzles map to nvtTPUHighFlow so a synced TPU-HF rack activates the H2C
 // change_filament_gcode TPU-kit branch. nvtHybrid is a slicer-only sentinel with no device
 // representation, so ToNozzleFlowType(nvtHybrid) falls through to NONE_FLOWTYPE.
@@ -24,6 +24,7 @@ NozzleFlowType DevNozzle::ToNozzleFlowType(const NozzleVolumeType& type)
        case NozzleVolumeType::nvtStandard:    return NozzleFlowType::S_FLOW;
        case NozzleVolumeType::nvtHighFlow:    return NozzleFlowType::H_FLOW;
        case NozzleVolumeType::nvtTPUHighFlow: return NozzleFlowType::U_FLOW;
+        case NozzleVolumeType::nvtE3DHighFlow: return NozzleFlowType::E_FLOW;
        default: return NozzleFlowType::NONE_FLOWTYPE;
    }
 }
@@ -34,6 +35,7 @@ NozzleVolumeType DevNozzle::ToNozzleVolumeType(const NozzleFlowType& type)
        case NozzleFlowType::S_FLOW: return NozzleVolumeType::nvtStandard;
        case NozzleFlowType::H_FLOW: return NozzleVolumeType::nvtHighFlow;
        case NozzleFlowType::U_FLOW: return NozzleVolumeType::nvtTPUHighFlow;
+        case NozzleFlowType::E_FLOW: return NozzleVolumeType::nvtE3DHighFlow;
        default: {
            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << "nozzle flow type None convert to nozzle volume type Standard";
            return NozzleVolumeType::nvtStandard;
@@ -47,6 +49,7 @@ wxString DevNozzle::GetNozzleFlowTypeStr(NozzleFlowType type)
    case NozzleFlowType::H_FLOW: return _L("High Flow");
    case NozzleFlowType::S_FLOW: return _L("Standard");
    case NozzleFlowType::U_FLOW: return _L("TPU High Flow");
+    case NozzleFlowType::E_FLOW: return _L("E3D High Flow");
    default: break;
    }

@@ -61,6 +64,7 @@ std::string DevNozzle::GetNozzleFlowTypeString(NozzleFlowType type)
        case NozzleFlowType::H_FLOW: return "High Flow";
        case NozzleFlowType::S_FLOW: return "Standard";
        case NozzleFlowType::U_FLOW: return "TPU High Flow";
+        case NozzleFlowType::E_FLOW: return "E3D High Flow";
        default: return "Unknown";
    }
 }
@@ -73,6 +77,7 @@ std::string DevNozzle::ToNozzleFlowString(const NozzleFlowType& type)
        case NozzleFlowType::S_FLOW: return "Standard";
        case NozzleFlowType::H_FLOW: return "High Flow";
        case NozzleFlowType::U_FLOW: return "TPU High Flow";
+        case NozzleFlowType::E_FLOW: return "E3D High Flow";
        default: return std::string();
    }
 }
@@ -408,6 +413,7 @@ static unordered_map<string, NozzleFlowType> _str2_nozzle_flow_type = {
    {"X", NozzleFlowType::S_FLOW},
    {"E", NozzleFlowType::H_FLOW}, // E3D high-flow
    {"U", NozzleFlowType::U_FLOW}, // TPU 1.75 high-flow -> nvtTPUHighFlow
+    {"B", NozzleFlowType::E_FLOW}, // E3D High Flow -> nvtE3DHighFlow
 };

 static unordered_map<string, NozzleType> _str2_nozzle_type = {
@@ -12,8 +12,9 @@

 // Device flow-type mapping note (nozzle rack): the device U_FLOW value maps to nvtTPUHighFlow
 // (TPU High Flow), so a device-synced TPU-HF rack resolves to nvtTPUHighFlow and the H2C
-// change_filament_gcode TPU-kit branch can activate. nvtHybrid is a slicer-only sentinel with no
-// device representation, so it stays out of these device flow-type conversions.
+// change_filament_gcode TPU-kit branch can activate. E_FLOW maps to nvtE3DHighFlow. nvtHybrid is a
+// slicer-only sentinel with no device representation, so it stays out of these device flow-type
+// conversions.
 //
 // GetExtruderNozzleInfo (and its ExtruderNozzleInfos aggregate) is intentionally omitted here;
 // the SelectMachine slicing-vs-installed nozzle comparison collects its per-extruder NozzleDef
@@ -36,13 +37,13 @@ namespace Slic3r
       float           m_diameter = 0.0f;// unknown until reported by the printer

   public:
-       // flow/volume conversions (Standard / High Flow / TPU High Flow)
+       // flow/volume conversions (Standard / High Flow / TPU High Flow / E3D High Flow)
       static NozzleFlowType       ToNozzleFlowType(const NozzleVolumeType& type);
       static NozzleVolumeType     ToNozzleVolumeType(const NozzleFlowType& type);

       static wxString             GetNozzleFlowTypeStr(NozzleFlowType type);
-       static std::string          GetNozzleFlowTypeString(NozzleFlowType type);// untranslated literal ("High Flow"/"Standard"/"TPU High Flow") — the filament blacklist JSON matches these raw strings, so it must NOT use the translated GetNozzleFlowTypeStr (would break non-English locales)
-       static std::string          ToNozzleFlowString(const NozzleFlowType& type);// untranslated "Standard"/"High Flow"/"TPU High Flow" ("" for none) — the raw literal serialized into the get_auto_nozzle_mapping payload
+       static std::string          GetNozzleFlowTypeString(NozzleFlowType type);// untranslated literal ("High Flow"/"Standard"/"TPU High Flow"/"E3D High Flow") — the filament blacklist JSON matches these raw strings, so it must NOT use the translated GetNozzleFlowTypeStr (would break non-English locales)
+       static std::string          ToNozzleFlowString(const NozzleFlowType& type);// untranslated "Standard"/"High Flow"/"TPU High Flow"/"E3D High Flow" ("" for none) — the raw literal serialized into the get_auto_nozzle_mapping payload
       static wxString             GetNozzleTypeStr(NozzleType type);

   public:
@@ -347,6 +347,10 @@ static wxString _generate_nozzle_id(NozzleVolumeType nozzle_type, const std::str
        nozzle_id += "H";
        break;
    }
+    case NozzleVolumeType::nvtE3DHighFlow: {
+        nozzle_id += "B";
+        break;
+    }
    default:
        nozzle_id += "H";
        break;
@@ -368,6 +372,8 @@ NozzleVolumeType convert_to_nozzle_type(const std::string &str)
        res = NozzleVolumeType::nvtStandard;
    else if (str[1] == 'H')
        res = NozzleVolumeType::nvtHighFlow;
+    else if (str[1] == 'B')
+        res = NozzleVolumeType::nvtE3DHighFlow;
    return res;
 }

@@ -566,7 +566,8 @@ std::vector<int> SeparatedDragDropPanel::GetHighFlowFilaments() const
    const int right_eid = 1;
    if (nozzle_volumes->values.size() > right_eid) {
        int volume_type = nozzle_volumes->values[right_eid];
-        if (volume_type == static_cast<int>(NozzleVolumeType::nvtHighFlow)) {
+        if (volume_type == static_cast<int>(NozzleVolumeType::nvtHighFlow) ||
+            volume_type == static_cast<int>(NozzleVolumeType::nvtE3DHighFlow)) {
            return m_unified_panel->GetAllFilaments();
        }
    }
@@ -185,6 +185,12 @@ std::vector<int> FilamentMapManualPanel::GetFilamentVolumeMaps() const
    auto preset_bundle        = wxGetApp().preset_bundle;
    auto proj_config          = preset_bundle->project_config;
    auto nozzle_volume_values = proj_config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type")->values;
+    // The high-flow panel of the right extruder also holds an E3D High Flow nozzle; keep that type
+    // instead of writing plain High Flow, which the extruder does not have.
+    const int  right_extruder_id      = 1;
+    const bool right_e3d_high_flow    = nozzle_volume_values.size() > right_extruder_id &&
+                                        nozzle_volume_values[right_extruder_id] == static_cast<int>(NozzleVolumeType::nvtE3DHighFlow);
+    const int  right_high_flow_volume = static_cast<int>(right_e3d_high_flow ? NozzleVolumeType::nvtE3DHighFlow : NozzleVolumeType::nvtHighFlow);

    for (int i = 0; i < (int) volume_map.size(); ++i) {
        int filament_id = i + 1;
@@ -199,7 +205,7 @@ std::vector<int> FilamentMapManualPanel::GetFilamentVolumeMaps() const
            }
        }
        else if (std::find(right_high_flow_filaments.begin(), right_high_flow_filaments.end(), filament_id) != right_high_flow_filaments.end()) {
-            volume_map[i] = static_cast<int>(NozzleVolumeType::nvtHighFlow);
+            volume_map[i] = right_high_flow_volume;
        }
        else if (std::find(right_standard_filaments.begin(), right_standard_filaments.end(), filament_id) != right_standard_filaments.end()) {
            volume_map[i] = static_cast<int>(NozzleVolumeType::nvtStandard);
@@ -605,15 +605,50 @@ private:
    bool                  m_enabled{false};
 };

+// The nozzle rows are set in the small body font their "T1" prefix and diameter readout use, so the
+// combos of a row drop from the Body_14 they are created with to match, instead of towering over
+// the labels next to them.
+static void use_nozzle_row_font(ComboBox *combo)
+{
+    // A read-only combo draws its value with the font of the TextInput it is built on, and its
+    // dropped list carries a font of its own.
+    combo->SetFont(Label::Body_10);
+    combo->GetDropDown().SetFont(Label::Body_10);
+
+    // A row is as tall as the tags of the variant switch: a line of Body_10 text plus the 3 points of
+    // padding they put above and below it. TextInput::messureSize() instead sizes a combo as its
+    // (hidden) text control plus 8, and on macOS that control's best height is a fixed 16 points
+    // whatever font it carries, so the box would keep the height of the Body_14 it was created with.
+    // Handing the control the height the row asks for, less those 8 points, keeps messureSize()'s own
+    // arithmetic landing on the small box however often it re-measures.
+    const int row_height = combo->GetTextExtent("0.4 mm").y + 2 * combo->FromDIP(3);
+    auto *text_ctrl = combo->GetTextCtrl();
+    text_ctrl->SetFont(Label::Body_10);
+    text_ctrl->SetInitialSize(wxSize(text_ctrl->GetBestSize().x, row_height - 8));
+
+    combo->SetMinSize(wxSize(combo->GetMinSize().x, row_height));
+    combo->SetSize(wxSize(combo->GetSize().x, row_height));
+}
+
 struct ExtruderGroup : StaticBox
 {
+    // One nozzle row: the tool prefix ("T1"…"Tn", shown only when the group lists several
+    // extruders) plus the nozzle readout and flow combo of a single extruder. Rows are appended on
+    // demand and never destroyed, so an event handler may capture its row index for the lifetime
+    // of the group.
+    struct NozzleRow
+    {
+        Label *    prefix         = nullptr;
+        Label *    diameter_label = nullptr; // read-only nozzle diameter of this extruder
+        ComboBox * flow           = nullptr;
+    };
+
    ExtruderGroup(wxWindow * parent, int index, wxString const &title);
    wxBoxSizer *      sizer        = nullptr;
    HoverLabel *      hover_label  = nullptr;
    wxStaticText*     ams_label{nullptr};
    ScalableButton *  btn_edit     = nullptr;
    ComboBox *        combo_diameter = nullptr;
-    ComboBox *        combo_flow = nullptr;
    AMSPreview *      ams[4]       = {nullptr};
    wxStaticText     *ams_not_installed_msg{nullptr};
    ScalableButton *  btn_up{nullptr};
@@ -627,6 +662,23 @@ struct ExtruderGroup : StaticBox
    std::vector<AMSinfo> ams_1;
    wxString          diameter;

+    std::vector<NozzleRow> rows;                  // rows[0] always exists, one row per extruder when multi
+    size_t                 nozzle_row_count = 0;  // rows currently shown
+    wxBoxSizer *           row_columns[2]   = {}; // row i is dealt into column i % 2
+    int                    group_index      = -1; // ctor index, the extruder a single-row group edits
+
+    // Show `count` nozzle rows, one per extruder, each prefixed with T<index> when count > 1.
+    void   SetNozzleRowCount(size_t count);
+    size_t NozzleRowCount() const { return nozzle_row_count; }
+    // Nozzle diameter readout of the shown rows, one value per extruder. A listing card cannot edit
+    // it: the diameter belongs to the machine variant the printer preset selects, not to the extruder.
+    void   SetRowDiameters(const std::vector<double> &diameters);
+
+    NozzleRow create_nozzle_row();
+    // Widths the prefix and diameter labels of the visible rows so that the flow combos of a column
+    // line up.
+    void update_row_widths();
+
    void set_ams_count(int n4, int n1)
    {
        if (n4 == ams_n4 && n1 == ams_n1)
@@ -657,7 +709,12 @@ struct ExtruderGroup : StaticBox
        btn_up->msw_rescale();
        btn_down->msw_rescale();
        combo_diameter->Rescale();
-        combo_flow->Rescale();
+        for (const NozzleRow &row : rows) {
+            row.prefix->SetFont(Label::Body_10.Bold());
+            row.diameter_label->SetFont(Label::Body_10);
+            row.flow->Rescale();
+        }
+        update_row_widths();
        for (int i = 0; i < 4; ++i)
            ams[i]->msw_rescale();
    }
@@ -668,6 +725,10 @@ struct ExtruderGroup : StaticBox
            hover_label->sys_color_changed();
        if (btn_edit)
            btn_edit->SetBackgroundColour(extruder_group_chip_bg());
+        for (const NozzleRow &row : rows) {
+            row.prefix->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
+            row.diameter_label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
+        }
        Refresh();
    }
 };
@@ -691,11 +752,12 @@ struct Sidebar::priv
    ScalableButton *      btn_edit_printer    = nullptr;
    ScalableButton *      btn_connect_printer = nullptr;

-    // Nozzle diameter
+    // Printer variant switch, titled "Variant": the combo lists the variants (nozzle sizes) of the
+    // current machine model and picking one switches the printer preset.
    StaticBox *     panel_nozzle_dia  = nullptr;
    Label *         label_nozzle_title= nullptr;
    ComboBox *      combo_nozzle_dia  = nullptr;
-    Label *         label_nozzle_type = nullptr;
+    Label *         label_nozzle_type = nullptr; // read-only nozzle material, one-row layouts only

    // Printer - bed
    StaticBox *     panel_printer_bed = nullptr;
@@ -809,6 +871,8 @@ struct Sidebar::priv
    // otherwise reuses the app_config-cached option when the machine's nozzle config is unchanged.
    std::optional<NozzleOption> get_nozzle_options(MachineObject* obj, int extruder_count, bool support_multi_nozzle, bool is_manual);
    bool switch_diameter(bool single);
+    // Switch to the printer preset offering `diameter`.
+    bool switch_diameter_to(const wxString &diameter);
    void update_sync_status(const MachineObject* obj);

    // Filament Track Switch (H2-family accessory): true only when the connected printer is the
@@ -918,11 +982,19 @@ void Sidebar::priv::layout_printer(bool isBBL, bool isDual)
        int extruder_count = 0;
        const bool has_flow_variant = cfg.support_different_extruders(extruder_count);

-        panel_nozzle_dia->Show(!has_flow_variant);
-        extruder_single_sizer->Show(has_flow_variant);
+        // ORCA: a non-Bambu printer with several extruders lists one nozzle row per tool; Bambu's own
+        // multi-extruder printers keep the left/right pair above.
+        const bool multi_extruder_rows = !preset_bundle.is_bbl_vendor() && extruder_count > 1;
+
+        // The variant box switches the machine variant. The card below lists the nozzles when there
+        // are flow variants to choose or several extruders to show; otherwise the box says it all.
+        panel_nozzle_dia->Show(true);
+        extruder_single_sizer->Show(has_flow_variant || multi_extruder_rows);
+        single_extruder->SetNozzleRowCount(multi_extruder_rows ? size_t(extruder_count) : 1);
    } else {
        panel_nozzle_dia->Show(false);
        extruder_single_sizer->Show(false);
+        single_extruder->SetNozzleRowCount(1);
    }

    // ORCA ensure printer section is visible after changing printer from printer selection dialog
@@ -1319,7 +1391,7 @@ public:
 };

 ExtruderGroup::ExtruderGroup(wxWindow * parent, int index, wxString const &title)
-    : StaticBox(parent)
+    : StaticBox(parent), group_index(index)
 {
    SetFont(Label::Body_10);
    SetForegroundColour(wxColour("#CECECE"));
@@ -1332,29 +1404,13 @@ ExtruderGroup::ExtruderGroup(wxWindow * parent, int index, wxString const &title
    hover_label = new HoverLabel(this, title);
    hover_label->SetPosition(wxPoint(FromDIP(PRINTER_PANEL_RADIUS), 0)); // position it without putting in a sizer so it will look like title

-    // Nozzle
+    // Nozzle. Only the dual left/right cards show this combo: it is how they ask which nozzle the
+    // project should print with. Every other card reads the diameter out as text.
    auto combo_diameter = new ComboBox(this, wxID_ANY, wxString(""), wxDefaultPosition, wxDefaultSize, 0, nullptr, wxCB_READONLY);
    this->combo_diameter = combo_diameter;
    combo_diameter->SetToolTip(_L("Diameter"));
-
-    // Flow
-    auto combo_flow = new ComboBox(this, wxID_ANY, wxString(""), wxDefaultPosition, wxDefaultSize, 0, nullptr, wxCB_READONLY);
-    combo_flow->GetDropDown().SetUseContentWidth(true);
-    combo_flow->Bind(wxEVT_COMBOBOX, [index, combo_flow](wxCommandEvent &evt) {
-        auto printer_tab = dynamic_cast<TabPrinter *>(wxGetApp().get_tab(Preset::TYPE_PRINTER));
-        NozzleVolumeType volume_type = NozzleVolumeType(intptr_t(combo_flow->GetClientData(evt.GetInt())));
-        printer_tab->set_extruder_volume_type(index, volume_type);
-        auto plater = GUI::wxGetApp().plater();
-        if (plater) {
-            // A new Flow type invalidates the per-filament volume choices stored on the
-            // plates for this extruder; rewrite them so the next apply/grouping sees the
-            // selected volume instead of a stale one.
-            plater->update_filament_volume_map(index, static_cast<int>(volume_type));
-            plater->update_machine_sync_status();
-        }
-    });
-    this->combo_flow = combo_flow;
-    combo_flow->SetToolTip(_L("Flow"));
+    combo_diameter->Show(index >= 0);
+    use_nozzle_row_font(combo_diameter);

    // AMS
    auto ams_panel = new wxPanel(this, wxID_ANY);
@@ -1440,10 +1496,6 @@ ExtruderGroup::ExtruderGroup(wxWindow * parent, int index, wxString const &title
    btn_down->Hide();

    wxBoxSizer *vsizer = new wxBoxSizer(wxVERTICAL);
-    wxBoxSizer *hsizer = new wxBoxSizer(wxHORIZONTAL);
-
-    hsizer->Add(combo_diameter, 1, wxRIGHT, FromDIP(5));
-    hsizer->Add(combo_flow    , 1);

    vsizer->AddSpacer(FromDIP(16)); // spacing for title and control
    if (index < 0) {
@@ -1452,14 +1504,137 @@ ExtruderGroup::ExtruderGroup(wxWindow * parent, int index, wxString const &title
        vsizer->Add(ams_panel, 0, wxEXPAND | wxLEFT | wxRIGHT , FromDIP(5));
        vsizer->AddSpacer(FromDIP(2));
    }
-    vsizer->Add(hsizer, 0, wxEXPAND | wxLEFT | wxRIGHT | wxBOTTOM, FromDIP(5));

+    // Nozzle rows. The first one is the only one for a printer whose nozzles are not listed
+    // individually; a multi-extruder printer grows one row per tool (see SetNozzleRowCount).
+    // The rows are dealt into two columns, which halves the height of a long tool list; the second
+    // column empties itself when there is a single row, so a one-row card still spans the width.
+    auto rows_sizer = new wxBoxSizer(wxHORIZONTAL);
+    for (wxBoxSizer *&column : row_columns) {
+        column = new wxBoxSizer(wxVERTICAL);
+        rows_sizer->Add(column, 1, wxEXPAND);
+    }
+    vsizer->Add(rows_sizer, 0, wxEXPAND);
+    sizer = vsizer; // the floating filament-switch icon positions itself against this card
    SetSizer(vsizer);
+    SetNozzleRowCount(1);
+
    Layout();

    AMSCountPopupWindow::UpdateAMSCount(index < 0 ? 0 : index, this);
 }

+ExtruderGroup::NozzleRow ExtruderGroup::create_nozzle_row()
+{
+    const size_t row_index = rows.size();
+    NozzleRow row;
+
+    row.prefix = new Label(this, Label::Body_10.Bold());
+    row.prefix->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
+    row.prefix->SetLabelText(wxString::Format("T%d", int(row_index) + 1));
+    row.prefix->Hide();
+
+    row.diameter_label = new Label(this, Label::Body_10);
+    row.diameter_label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
+    row.diameter_label->Hide();
+
+    auto combo_flow = new ComboBox(this, wxID_ANY, wxString(""), wxDefaultPosition, wxDefaultSize, 0, nullptr, wxCB_READONLY);
+    combo_flow->GetDropDown().SetUseContentWidth(true);
+    combo_flow->Bind(wxEVT_COMBOBOX, [this, row_index, combo_flow](wxCommandEvent &evt) {
+        // A one-row card edits the extruder it was created for, a multi-row card one extruder per row.
+        const int index = nozzle_row_count > 1 ? int(row_index) : group_index;
+        auto printer_tab = dynamic_cast<TabPrinter *>(wxGetApp().get_tab(Preset::TYPE_PRINTER));
+        NozzleVolumeType volume_type = NozzleVolumeType(intptr_t(combo_flow->GetClientData(evt.GetInt())));
+        printer_tab->set_extruder_volume_type(index, volume_type);
+        auto plater = GUI::wxGetApp().plater();
+        if (plater) {
+            // A new Flow type invalidates the per-filament volume choices stored on the
+            // plates for this extruder; rewrite them so the next apply/grouping sees the
+            // selected volume instead of a stale one.
+            plater->update_filament_volume_map(index, static_cast<int>(volume_type));
+            plater->update_machine_sync_status();
+        }
+    });
+    combo_flow->SetToolTip(_L("Flow"));
+    row.flow = combo_flow;
+    use_nozzle_row_font(combo_flow);
+
+    auto row_sizer = new wxBoxSizer(wxHORIZONTAL);
+    row_sizer->Add(row.prefix, 0, wxALIGN_CENTER_VERTICAL | wxRIGHT, FromDIP(3));
+    if (row_index == 0)
+        row_sizer->Add(combo_diameter, 1, wxRIGHT, FromDIP(5));
+    row_sizer->Add(row.diameter_label, 0, wxALIGN_CENTER_VERTICAL | wxRIGHT, FromDIP(5));
+    row_sizer->Add(row.flow, 1);
+    // Row-major: T1 T2 on the first line, T3 T4 on the second, and so on.
+    row_columns[row_index % 2]->Add(row_sizer, 0, wxEXPAND | wxLEFT | wxRIGHT | wxBOTTOM, FromDIP(5));
+
+    return row;
+}
+
+void ExtruderGroup::update_row_widths()
+{
+    // Measured from the rows on screen rather than fixed, so no gap is reserved for a "T10" or a
+    // "0.25 mm" that no row carries while the flow combos of a column still line up.
+    wxSize prefix_width(0, -1);
+    wxSize diameter_width(0, -1);
+    for (const NozzleRow &row : rows) {
+        if (row.prefix->IsShown())
+            prefix_width.x = std::max(prefix_width.x, row.prefix->GetTextExtent(row.prefix->GetLabelText()).x);
+        if (row.diameter_label->IsShown())
+            diameter_width.x = std::max(diameter_width.x, row.diameter_label->GetTextExtent(row.diameter_label->GetLabelText()).x);
+    }
+    for (const NozzleRow &row : rows) {
+        row.prefix->SetMinSize(prefix_width);
+        row.diameter_label->SetMinSize(diameter_width);
+    }
+}
+
+void ExtruderGroup::SetRowDiameters(const std::vector<double> &diameters)
+{
+    for (size_t i = 0; i < std::min(nozzle_row_count, diameters.size()); ++i) {
+        // Spelled like the calibration dialogs spell a nozzle diameter, "0.4 mm".
+        const wxString text = from_u8(get_diameter_string(diameters[i])) + " mm";
+        rows[i].diameter_label->SetLabelText(text);
+        rows[i].diameter_label->SetToolTip(text);
+    }
+    update_row_widths();
+    Layout();
+}
+
+void ExtruderGroup::SetNozzleRowCount(size_t count)
+{
+    const size_t row_count = std::min(count, size_t(MAXIMUM_EXTRUDER_NUMBER));
+    if (row_count == nozzle_row_count)
+        return;
+    nozzle_row_count = row_count;
+
+    // Every row names its tool as soon as there is more than one, so a single-nozzle card keeps the
+    // plain "Nozzle" look. A row is shown by showing its widgets: a sizer item holding a sub-sizer
+    // reports itself as shown while any of its windows is, so hiding the sub-sizer alone would
+    // leave the row in the layout.
+    for (size_t i = 0; i < row_count; ++i) {
+        if (i >= rows.size())
+            rows.push_back(create_nozzle_row());
+        rows[i].prefix->Show(row_count > 1);
+        rows[i].diameter_label->Show(group_index < 0); // the dual left/right cards show combo_diameter
+        // The flow combo's own visibility is decided with its choices, see update_extruder_variant.
+    }
+    for (size_t i = row_count; i < rows.size(); ++i) {
+        rows[i].prefix->Hide();
+        rows[i].diameter_label->Hide();
+        rows[i].flow->Hide();
+    }
+
+    // The rows just changed: re-measure them, then let the card and its containers give it the new room.
+    update_row_widths();
+    Layout();
+    if (wxWindow *parent = GetParent()) {
+        parent->Layout();
+        if (wxWindow *grand_parent = parent->GetParent())
+            grand_parent->Layout();
+    }
+}
+
 void ExtruderGroup::update_ams()
 {
    static AMSinfo info4;
@@ -1588,9 +1763,19 @@ bool Sidebar::priv::switch_diameter(bool single)
            diameter = diameter_left;
        }
    }
-    
+
+    return switch_diameter_to(diameter);
+}
+
+bool Sidebar::priv::switch_diameter_to(const wxString &diameter)
+{
    // ORCA: Check if the selected diameter matches the current nozzle diameter in the config
    Preset& printer_preset = wxGetApp().preset_bundle->printers.get_edited_preset();
+    // The combo lists printer variants, and the variant of a mixed-nozzle machine ("0.4+0.6") is no
+    // single extruder's diameter, so the preset's own variant answers first.
+    if (printer_preset.config.opt_string("printer_variant") == diameter.ToStdString()) {
+        return true;
+    }
    auto* nozzle_diameter = dynamic_cast<const ConfigOptionFloats*>(printer_preset.config.option("nozzle_diameter"));
    if (nozzle_diameter && nozzle_diameter->size() > 0) {
        auto current_nozzle_dia = get_diameter_string(nozzle_diameter->values[0]);
@@ -2679,7 +2864,8 @@ Sidebar::Sidebar(Plater *parent)
            p->combo_nozzle_dia->wxEvtHandler::ProcessEvent(evt);
        });

-        p->label_nozzle_title = new Label(p->panel_nozzle_dia, _L("Nozzle"), LB_PROPAGATE_MOUSE_EVENT);
+        // "Variant", not "Nozzle": picking one switches the printer preset (see panel_nozzle_dia).
+        p->label_nozzle_title = new Label(p->panel_nozzle_dia, _L("Variant"), LB_PROPAGATE_MOUSE_EVENT);
        p->label_nozzle_title->SetFont(Label::Body_10);

        p->combo_nozzle_dia = new ComboBox(p->panel_nozzle_dia, wxID_ANY, wxString(""), wxDefaultPosition, wxDefaultSize, 0, nullptr, wxCB_READONLY);
@@ -2688,12 +2874,15 @@ Sidebar::Sidebar(Plater *parent)
        p->combo_nozzle_dia->SetMinSize(FromDIP(wxSize(PRINTER_PANEL_SIZE.GetWidth() - 4, 26))); // requires a static value in here
        p->combo_nozzle_dia->SetMaxSize(FromDIP(wxSize(PRINTER_PANEL_SIZE.GetWidth() - 4, 26))); // using -1 with wxEXPAND has issues
        p->combo_nozzle_dia->Bind(wxEVT_COMBOBOX, [this](auto &e) {
-            auto evt_combo = (*p->single_extruder).combo_diameter;
-            evt_combo->SetSelection(e.GetSelection());
-            wxCommandEvent evt(wxEVT_COMBOBOX, evt_combo->GetId());
-            evt.SetEventObject(evt_combo);
-            evt.SetInt(e.GetSelection());
-            wxPostEvent(evt_combo, evt);
+            // This box is the machine-variant selector, so it switches the printer preset directly
+            // instead of feeding an extruder card's combo. Deferred, because switching preset
+            // rebuilds this very combo.
+            const wxString diameter = p->combo_nozzle_dia->GetValue();
+            p->combo_nozzle_dia->CallAfter([this, diameter]() {
+                p->is_switching_diameter = true;
+                p->switch_diameter_to(diameter);
+                p->is_switching_diameter = false;
+            });
            e.Skip();
        });
        // ORCA paint whole combobox on focus
@@ -3673,8 +3862,16 @@ void Sidebar::update_presets(Preset::Type preset_type)
        auto diameters = wxGetApp().preset_bundle->printers.diameters_of_selected_printer();
        auto diameter = printer_preset.config.opt_string("printer_variant");
        auto extruder_max_nozzle_count = printer_preset.config.option<ConfigOptionIntsNullable>("extruder_max_nozzle_count");
-        auto update_extruder_variant = [printer_model, extruders_def, extruders, nozzle_volumes_def, nozzle_volumes, extruder_variants,diameter,extruder_max_nozzle_count](ExtruderGroup & extruder, int index) {
-            extruder.combo_flow->Clear();
+        auto update_extruder_variant = [printer_model, extruders_def, extruders, nozzle_volumes_def, nozzle_volumes, extruder_variants,diameter,extruder_max_nozzle_count](ExtruderGroup & extruder, size_t row, int index) {
+            ComboBox *combo_flow = extruder.rows[row].flow;
+            combo_flow->Clear();
+            // A profile may leave the per-extruder lists shorter than the nozzle count (they are
+            // padded when the printer is loaded, but a hand-written preset need not be).
+            if (index >= int(extruder_variants->values.size()) || index >= int(extruders->values.size()) ||
+                index >= int(nozzle_volumes->values.size())) {
+                combo_flow->Hide();
+                return;
+            }
            auto type = extruders_def->enum_labels[extruders->values[index]];
            int select = -1;
            for (size_t i = 0; i < nozzle_volumes_def->enum_labels.size(); ++i) {
@@ -3684,26 +3881,36 @@ void Sidebar::update_presets(Preset::Type preset_type)
                if (boost::algorithm::contains(extruder_variants->values[index], type + " " + nozzle_volumes_def->enum_labels[i]) ||
                    (extruder_max_nozzle_count->get_at(index) > 1 && extruder_max_nozzle_count->get_at(index) != ConfigOptionIntsNullable::nil_value() &&
                    nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]) == nvtHybrid)) {
-                    if (nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]) == NozzleVolumeType::nvtHighFlow &&(diameter == "0.2" ||
+                    auto cur_volume_type = nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]);
+                    // Defensive: profiles restrict E3D to 0.4 / 0.6; keep it out elsewhere.
+                    if (cur_volume_type == NozzleVolumeType::nvtE3DHighFlow && diameter != "0.4" && diameter != "0.6")
+                        continue;
+                    if (cur_volume_type == NozzleVolumeType::nvtHighFlow && (diameter == "0.2" ||
                        is_skip_high_flow_printer(printer_model)))
                        continue;
-                    if (nozzle_volumes->values[index] == i)
-                        select = extruder.combo_flow->GetCount();
-                    extruder.combo_flow->Append(_L(nozzle_volumes_def->enum_labels[i]), {}, (void*)i);
+                    // The client data is the enum value, not the label position: E3D High Flow is 5
+                    // but sits at position 4, and a position would write an invalid type.
+                    if (nozzle_volumes->values[index] == cur_volume_type)
+                        select = combo_flow->GetCount();
+                    combo_flow->Append(_L(nozzle_volumes_def->enum_labels[i]), {}, (void*)(intptr_t)cur_volume_type);
                }
            }
            if (select == -1)
-                select = extruder.combo_flow->GetCount() - 1;
-            extruder.combo_flow->SetSelection(select);
+                select = combo_flow->GetCount() - 1;
+            combo_flow->SetSelection(select);
+            // No flow variant for this extruder: the diameter keeps the whole row.
+            combo_flow->Show(combo_flow->GetCount() > 0);
        };

        auto update_extruder_diameter = [&diameters, &nozzle_diameter](int extruder_index,ExtruderGroup & extruder) {
            extruder.combo_diameter->Clear();
+            if (extruder_index >= int(nozzle_diameter->values.size()))
+                return;
            int select = -1;
            // ORCA get the actual nozzle diameter from printer config
            auto nozzle_dia = get_diameter_string(nozzle_diameter->values[extruder_index]);
            // ORCA try to add nozzle diameter from config if list is empty. fixes blank nozzle combo box when preset has no alias
-            if(diameters[0].empty() && !nozzle_dia.empty()){
+            if(!diameters.empty() && diameters[0].empty() && !nozzle_dia.empty()){
                diameters[0] = nozzle_dia;
            }
            // Orca: Check if the actual nozzle diameter exists in the list, if not add it as a custom option
@@ -3719,14 +3926,15 @@ void Sidebar::update_presets(Preset::Type preset_type)
            extruder.diameter = nozzle_dia;
        };
        auto image_path = get_cur_select_bed_image();
-        if (is_dual_extruder) {
+        const bool multi_extruder_rows = p->single_extruder->NozzleRowCount() > 1;
+        if (is_dual_extruder && !multi_extruder_rows) {
            std::string printer_type = printer_preset.get_printer_type(wxGetApp().preset_bundle);
            p->left_extruder->SetTitle(_L(DevPrinterConfigUtil::get_toolhead_display_name(printer_type, DEPUTY_EXTRUDER_ID, ToolHeadComponent::Nozzle, ToolHeadNameCase::TitleCase)));
            p->right_extruder->SetTitle(_L(DevPrinterConfigUtil::get_toolhead_display_name(printer_type, MAIN_EXTRUDER_ID, ToolHeadComponent::Nozzle, ToolHeadNameCase::TitleCase)));
            AMSCountPopupWindow::UpdateAMSCount(0, p->left_extruder);
            AMSCountPopupWindow::UpdateAMSCount(1, p->right_extruder);
-            update_extruder_variant(*p->left_extruder, 0);
-            update_extruder_variant(*p->right_extruder, 1);
+            update_extruder_variant(*p->left_extruder, 0, 0);
+            update_extruder_variant(*p->right_extruder, 0, 1);
            //if (!p->is_switching_diameter) {
                update_extruder_diameter(0, *p->left_extruder);
                update_extruder_diameter(1, *p->right_extruder);
@@ -3734,15 +3942,27 @@ void Sidebar::update_presets(Preset::Type preset_type)
            p->image_printer_bed->SetBitmap(create_scaled_bitmap(image_path, this, PRINTER_THUMBNAIL_SIZE.GetHeight()));
        } else {
            AMSCountPopupWindow::UpdateAMSCount(0, p->single_extruder);
-            update_extruder_variant(*p->single_extruder, 0);
+            for (size_t row = 0; row < p->single_extruder->NozzleRowCount(); ++row)
+                update_extruder_variant(*p->single_extruder, row, int(row));
            //if (!p->is_switching_diameter)
                update_extruder_diameter(0, *p->single_extruder);
+            // The card reads the nozzles out, the variant box above is what switches the machine.
+            p->single_extruder->SetRowDiameters(nozzle_diameter->values);
+            if (multi_extruder_rows) {
+                // The hidden left/right cards keep mirroring the first extruders' diameters: the
+                // device sync path (a connected Bambu printer or a printer agent) still reads them.
+                update_extruder_diameter(0, *p->left_extruder);
+                update_extruder_diameter(1, *p->right_extruder);
+            }

            // ORCA sync unified nozzle combo box
            p->combo_nozzle_dia->Clear();
            for (size_t i = 0; i < diameters.size(); ++i)
                p->combo_nozzle_dia->Append(diameters[i], {});
-            p->combo_nozzle_dia->SetSelection((*p->single_extruder).combo_diameter->GetSelection());
+            // Prefer the variant the preset names: a mixed-nozzle machine reads "0.4+0.6", which is
+            // no single extruder's diameter.
+            const int variant = p->combo_nozzle_dia->FindString(diameter);
+            p->combo_nozzle_dia->SetSelection(variant != wxNOT_FOUND ? variant : (*p->single_extruder).combo_diameter->GetSelection());
            
            // ORCA update nozzle type
            const auto& full_config = wxGetApp().preset_bundle->full_config();
@@ -1793,6 +1793,7 @@ wxString PrinterPartsDialog::GetString(NozzleFlowType nozzle_flow_type) const {
        case Slic3r::S_FLOW: return _L("Standard");
        case Slic3r::H_FLOW: return _L("High flow");
        case Slic3r::U_FLOW: return _L("TPU High flow");
+        case Slic3r::E_FLOW: return _L("E3D High Flow");
        default: break;
    }

@@ -75,6 +75,9 @@ std::string get_nozzle_volume_type_cloud_string(NozzleVolumeType nozzle_volume_t
    else if (nozzle_volume_type == NozzleVolumeType::nvtTPUHighFlow) {
        return "tpu_high_flow";
    }
+    else if (nozzle_volume_type == NozzleVolumeType::nvtE3DHighFlow) {
+        return "e3d_high_flow";
+    }
    else if (nozzle_volume_type == NozzleVolumeType::nvtHybrid) {
        // to be supported
        return "hybrid_flow";
@@ -1516,6 +1516,8 @@ bool SyncAmsInfoDialog::is_nozzle_type_match(DevExtderSystem data, wxString &err
                used_extruders_flow[used_extruders[i]] = "Standard";
            } else if (nozzle_volume_type == NozzleVolumeType::nvtTPUHighFlow) {
                used_extruders_flow[used_extruders[i]] = "TPU High Flow";
+            } else if (nozzle_volume_type == NozzleVolumeType::nvtE3DHighFlow) {
+                used_extruders_flow[used_extruders[i]] = "E3D High Flow";
            } else {
                used_extruders_flow[used_extruders[i]] = "High Flow";
            }
@@ -1533,6 +1535,8 @@ bool SyncAmsInfoDialog::is_nozzle_type_match(DevExtderSystem data, wxString &err
            flow_type_of_machine.push_back("Standard");
        } else if (it->GetNozzleFlowType() == NozzleFlowType::U_FLOW) {
            flow_type_of_machine.push_back("TPU High Flow");
+        } else if (it->GetNozzleFlowType() == NozzleFlowType::E_FLOW) {
+            flow_type_of_machine.push_back("E3D High Flow");
        }
    }

@@ -506,7 +506,7 @@ void Tab::create_preset_tab()

    if (dynamic_cast<TabPrinter *>(this) || dynamic_cast<TabPrint *>(this)) {
        m_extruder_switch = new MultiSwitchButton(panel);
-        m_extruder_switch->SetMaxSize({em_unit(this) * 40, -1});
+        m_extruder_switch->SetFitToOptions();
        m_extruder_switch->Bind(wxCUSTOMEVT_MULTISWITCH_SELECTION, [this](auto &evt) {
            evt.Skip();
            int selection = evt.GetInt();
@@ -539,7 +539,8 @@ void Tab::create_preset_tab()
        auto right_sizer = new wxBoxSizer(wxHORIZONTAL);

        m_variant_sizer->AddStretchSpacer(1);
-        m_variant_sizer->Add(m_extruder_switch, 0, wxALIGN_CENTER, 0);
+        // Orca: proportion 1 lets a narrow row squeeze the switch, which then scrolls its buttons.
+        m_variant_sizer->Add(m_extruder_switch, 1, wxALIGN_CENTER, 0);
        m_variant_sizer->Add(right_sizer, 1, wxALIGN_CENTER);
        right_sizer->AddStretchSpacer(1);
        right_sizer->Add(m_extruder_sync_box, 0, wxALIGN_CENTER | wxRIGHT, m_em_unit);
@@ -8172,7 +8173,7 @@ void Tab::update_extruder_variants(int extruder_id, bool reload)

        // Orca: a non-Bambu dual-nozzle printer has two extruders but a single variant column, so
        // the nozzle switch and sync button have nothing to act on. Only enable with real variants.
-        if (extruder_nums == 2 && m_preset_bundle->support_different_extruders()) {
+        if (extruder_nums >= 2 && m_preset_bundle->support_different_extruders()) {
            auto options = generate_extruder_options();
            m_extruder_switch->SetOptions(options);

@@ -8219,6 +8220,23 @@ void Tab::update_extruder_variants(int extruder_id, bool reload)
    }
 }

+// The variant switch tags are the narrowest place a volume type is named, so they abbreviate it;
+// the flow combo boxes and the Printer tab's parameter labels keep the full names.
+static wxString short_nozzle_volume_name(const std::string &volume_name)
+{
+    // Hybrid has no entry on purpose: it is never a variant string, and the switch lists its two
+    // sub-nozzle types as separate tags (see generate_extruder_options).
+    if (volume_name == "Standard")
+        return "SF";
+    if (volume_name == "High Flow")
+        return "HF";
+    if (volume_name == "TPU High Flow")
+        return "TPU HF";
+    if (volume_name == "E3D High Flow")
+        return "E3D HF";
+    return from_u8(volume_name);
+}
+
 std::vector<wxString> Tab::generate_extruder_options()
 {
    std::vector<wxString> options;
@@ -8259,7 +8277,7 @@ std::vector<wxString> Tab::generate_extruder_options()
                    nozzle = "";
                }
            }
-            options.push_back(wxString::Format(_L("%s: %s"), _L(drive), _L(nozzle)));
+            options.push_back(wxString::Format(_L("%s: %s"), _L(drive), short_nozzle_volume_name(nozzle)));
        }
        return options;
    }
@@ -8273,18 +8291,22 @@ std::vector<wxString> Tab::generate_extruder_options()
    }

    std::string pt = m_preset_bundle->printers.get_edited_preset().get_printer_type(m_preset_bundle);
+    // Orca: the main/deputy toolhead names describe a dual-nozzle printer, where extruder 0 is the
+    // left (deputy) and extruder 1 the right (main) nozzle. From three extruders on the tools are
+    // interchangeable, so name them by index instead of repeating one side.
    for (int i = 0; i < extruder_nums; ++i) {
-        int ext_id = (i == 0) ? DEPUTY_EXTRUDER_ID : MAIN_EXTRUDER_ID;
-        wxString extruder_name = _L(DevPrinterConfigUtil::get_toolhead_display_name(
-            pt, ext_id, ToolHeadComponent::Nozzle, ToolHeadNameCase::TitleCase, true));
+        wxString extruder_name = extruder_nums > 2 ? wxString::Format("T%d", i + 1) :
+                                                     _L(DevPrinterConfigUtil::get_toolhead_display_name(
+                                                         pt, (i == 0) ? DEPUTY_EXTRUDER_ID : MAIN_EXTRUDER_ID,
+                                                         ToolHeadComponent::Nozzle, ToolHeadNameCase::TitleCase, true));
        NozzleVolumeType volume_type = NozzleVolumeType(nozzle_volumes->values[i]);

        if (volume_type == NozzleVolumeType::nvtHybrid) {
-            options.push_back(wxString::Format(_L("%s: %s"), extruder_name, _L("Standard")));
-            options.push_back(wxString::Format(_L("%s: %s"), extruder_name, _L("High Flow")));
+            options.push_back(wxString::Format(_L("%s: %s"), extruder_name, short_nozzle_volume_name(get_nozzle_volume_type_string(NozzleVolumeType::nvtStandard))));
+            options.push_back(wxString::Format(_L("%s: %s"), extruder_name, short_nozzle_volume_name(get_nozzle_volume_type_string(NozzleVolumeType::nvtHighFlow))));
        } else {
-            wxString volume_name = get_nozzle_volume_type_name(volume_type);
-            options.push_back(wxString::Format(_L("%s: %s"), extruder_name, volume_name));
+            options.push_back(wxString::Format(_L("%s: %s"), extruder_name,
+                                               short_nozzle_volume_name(get_nozzle_volume_type_string(volume_type))));
        }
    }
    return options;
@@ -8315,7 +8337,10 @@ bool Tab::get_extruder_sync_enable_state(int extruder_id)
    Preset& printer_preset = m_preset_bundle->printers.get_edited_preset();
    auto nozzle_volumes = m_preset_bundle->project_config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type");
    auto extruders = printer_preset.config.option<ConfigOptionEnumsGeneric>("extruder_type");
-    if (nozzle_volumes->values.size() < 2 || extruders->values.size() < 2) {
+    // Orca: every rule below describes the two toolheads of a dual-nozzle printer as left/right.
+    // A printer with any other extruder count has no single counterpart to copy to, so it gets no
+    // sync button (a toolchanger would need a target to be chosen).
+    if (nozzle_volumes->values.size() != 2 || extruders->values.size() != 2) {
        return false;
    }

@@ -8456,6 +8481,10 @@ void Tab::sync_excluder()
            ExtruderType(extruders->values[extruder_id]), nozzle_type, variant_keys.second, stride);
    };
    int active_index = get_current_active_extruder();
+    // The button copies to the other toolhead, so it is only offered when that other one exists;
+    // without this the `1 - active_index` below would index an extruder that is not there.
+    if (!get_extruder_sync_enable_state(active_index))
+        return;
    auto active_nozzle = get_actual_nozzle_volume_type(active_index);
    int from_index = get_index_for_extruder(active_index, active_nozzle);
    int dest_index = get_index_for_extruder(1 - active_index, active_nozzle);
@@ -70,8 +70,8 @@ int getExtruderNozzleCountTotal(PresetBundle *preset_bundle, int extruder_id)

 // ---- ManualNozzleCountDialog ----------------------------------------------------------------------------------

-ManualNozzleCountDialog::ManualNozzleCountDialog(
-    wxWindow *parent, NozzleVolumeType volume_type, int standard_count, int highflow_count, int max_nozzle_count, bool force_no_zero)
+ManualNozzleCountDialog::ManualNozzleCountDialog(wxWindow *parent, NozzleVolumeType volume_type, int standard_count, int highflow_count, int e3d_count,
+                                                 int max_nozzle_count, bool force_no_zero, const std::set<NozzleVolumeType> &supported_types)
    : DPIDialog(parent, wxID_ANY, _L("Set nozzle count"), wxDefaultPosition, wxDefaultSize, wxCAPTION | wxCLOSE_BOX)
 {
    SetBackgroundColour(*wxWHITE);
@@ -93,43 +93,39 @@ ManualNozzleCountDialog::ManualNozzleCountDialog(
    for (int i = 0; i <= max_nozzle_count; ++i)
        nozzle_choices.Add(wxString::Format("%d", i));

-    // A Hybrid extruder mixes Standard and High Flow nozzles, so it gets both count choices; the concrete
-    // types get exactly one.
-    if (volume_type == nvtStandard || volume_type == nvtHybrid) {
-        wxBoxSizer *standard_sizer = new wxBoxSizer(wxHORIZONTAL);
-        auto standard_label = new wxStaticText(content, wxID_ANY, _L(get_nozzle_volume_type_string(nvtStandard)), wxDefaultPosition, wxSize(FromDIP(100), -1));
-        standard_label->SetFont(Label::Body_14);
-        standard_label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
-        standard_sizer->Add(standard_label, 0, wxALIGN_CENTER_VERTICAL);
-        m_standard_choice = new ComboBox(content, wxID_ANY, "", wxDefaultPosition, wxSize(FromDIP(80), -1), 0, nullptr, wxCB_READONLY);
-        std::vector<wxString>::iterator iter;
-        for (iter = nozzle_choices.begin(); iter != nozzle_choices.end(); iter++)
-            m_standard_choice->Append(*iter);
-        m_standard_choice->SetSelection(standard_count);
-        standard_sizer->Add(m_standard_choice, 0, wxALIGN_CENTER_VERTICAL | wxLEFT, FromDIP(5));
-        choice_sizer->Add(standard_sizer, 0, wxTOP | wxRIGHT, FromDIP(15));
-    }
-    if (volume_type == nvtHighFlow || volume_type == nvtHybrid) {
-        wxBoxSizer *highflow_sizer = new wxBoxSizer(wxHORIZONTAL);
-        auto highflow_label = new wxStaticText(content, wxID_ANY, _L(get_nozzle_volume_type_string(nvtHighFlow)), wxDefaultPosition, wxSize(FromDIP(100), -1));
-        highflow_label->SetFont(Label::Body_14);
-        highflow_label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
-        highflow_sizer->Add(highflow_label, 0, wxALIGN_CENTER_VERTICAL);
-        m_highflow_choice = new ComboBox(content, wxID_ANY, "", wxDefaultPosition, wxSize(FromDIP(80), -1), 0, nullptr, wxCB_READONLY);
-        std::vector<wxString>::iterator iter;
-        for (iter = nozzle_choices.begin(); iter != nozzle_choices.end(); iter++)
-            m_highflow_choice->Append(*iter);
-        m_highflow_choice->SetSelection(highflow_count);
-        highflow_sizer->Add(m_highflow_choice, 0, wxALIGN_CENTER_VERTICAL | wxLEFT, FromDIP(5));
-        choice_sizer->Add(highflow_sizer, 0, wxTOP | wxRIGHT, FromDIP(15));
-    }
+    // A Hybrid extruder mixes several nozzle volume types, so it gets a count choice for each type the
+    // extruder actually has; a concrete type gets exactly its own, which it supports by definition.
+    auto shows = [volume_type, &supported_types](NozzleVolumeType type) {
+        return volume_type == type || (volume_type == nvtHybrid && (supported_types.empty() || supported_types.count(type) > 0));
+    };
+    auto add_count_choice = [this, content, choice_sizer, &nozzle_choices](NozzleVolumeType type, int count) {
+        wxBoxSizer *row_sizer = new wxBoxSizer(wxHORIZONTAL);
+        auto label = new wxStaticText(content, wxID_ANY, _L(get_nozzle_volume_type_string(type)), wxDefaultPosition, wxSize(FromDIP(100), -1));
+        label->SetFont(Label::Body_14);
+        label->SetForegroundColour(StateColor::darkModeColorFor(wxColour("#363636")));
+        row_sizer->Add(label, 0, wxALIGN_CENTER_VERTICAL);
+        auto choice = new ComboBox(content, wxID_ANY, "", wxDefaultPosition, wxSize(FromDIP(80), -1), 0, nullptr, wxCB_READONLY);
+        for (const wxString &item : nozzle_choices)
+            choice->Append(item);
+        choice->SetSelection(count);
+        row_sizer->Add(choice, 0, wxALIGN_CENTER_VERTICAL | wxLEFT, FromDIP(5));
+        choice_sizer->Add(row_sizer, 0, wxTOP | wxRIGHT, FromDIP(15));
+        return choice;
+    };
+    if (shows(nvtStandard))
+        m_standard_choice = add_count_choice(nvtStandard, standard_count);
+    if (shows(nvtHighFlow))
+        m_highflow_choice = add_count_choice(nvtHighFlow, highflow_count);
+    if (shows(nvtE3DHighFlow))
+        m_e3d_choice = add_count_choice(nvtE3DHighFlow, e3d_count);

    m_error_label = new wxStaticText(this, wxID_ANY, "");
    m_error_label->SetForegroundColour(wxColour("#E14747"));
    m_error_label->Hide();

-    auto update_nozzle_error = [this, force_no_zero, content, max_nozzle_count](int standard_count, int highflow_count) {
-        const int total_count = standard_count + highflow_count;
+    auto update_nozzle_error = [this, force_no_zero, content, max_nozzle_count](wxCommandEvent &e) {
+        // The Hybrid count is the sum over every choice on screen, whatever the extruder's own type.
+        const int total_count = GetNozzleCount(nvtHybrid);
        if (0 < total_count && total_count <= max_nozzle_count && m_error_label->IsShown()) {
            m_error_label->Hide();
            m_confirm_btn->Enable();
@@ -145,18 +141,12 @@ ManualNozzleCountDialog::ManualNozzleCountDialog(
            Layout();
            Fit();
        }
+        e.Skip();
    };

-    if (m_standard_choice)
-        m_standard_choice->Bind(wxEVT_COMBOBOX, [this, update_nozzle_error](wxCommandEvent &e) {
-            update_nozzle_error(m_standard_choice->GetSelection(), m_highflow_choice ? m_highflow_choice->GetSelection() : 0);
-            e.Skip();
-        });
-    if (m_highflow_choice)
-        m_highflow_choice->Bind(wxEVT_COMBOBOX, [this, update_nozzle_error](wxCommandEvent &e) {
-            update_nozzle_error(m_standard_choice ? m_standard_choice->GetSelection() : 0, m_highflow_choice->GetSelection());
-            e.Skip();
-        });
+    for (ComboBox *choice : {m_standard_choice, m_highflow_choice, m_e3d_choice})
+        if (choice)
+            choice->Bind(wxEVT_COMBOBOX, update_nozzle_error);

    content_sizer->Add(nozzle_icon, 0, wxALL | wxALIGN_CENTER_VERTICAL, FromDIP(15));
    content_sizer->Add(choice_sizer, 0, wxALIGN_CENTRE_VERTICAL);
@@ -181,9 +171,10 @@ int ManualNozzleCountDialog::GetNozzleCount(NozzleVolumeType volume_type) const
        return m_standard_choice ? m_standard_choice->GetSelection() : 0;
    if (volume_type == nvtHighFlow)
        return m_highflow_choice ? m_highflow_choice->GetSelection() : 0;
+    if (volume_type == nvtE3DHighFlow)
+        return m_e3d_choice ? m_e3d_choice->GetSelection() : 0;
    if (volume_type == nvtHybrid)
-        return (m_standard_choice ? m_standard_choice->GetSelection() : 0) +
-               (m_highflow_choice ? m_highflow_choice->GetSelection() : 0);
+        return GetNozzleCount(nvtStandard) + GetNozzleCount(nvtHighFlow) + GetNozzleCount(nvtE3DHighFlow);
    return 0;
 }

@@ -318,6 +309,7 @@ void manuallySetNozzleCount(int extruder_id)
    const NozzleVolumeType volume_type    = NozzleVolumeType(nozzle_volume_type_opt->values[extruder_id]);
    const int              standard_count = getExtruderNozzleCount(preset_bundle, extruder_id, nvtStandard);
    const int              highflow_count = getExtruderNozzleCount(preset_bundle, extruder_id, nvtHighFlow);
+    const int              e3d_count      = getExtruderNozzleCount(preset_bundle, extruder_id, nvtE3DHighFlow);

    // Require at least one nozzle for a Hybrid extruder (an empty mix is meaningless) and when the other
    // extruder currently has none.
@@ -325,11 +317,19 @@ void manuallySetNozzleCount(int extruder_id)
    if (nozzle_volume_type_opt->values.size() > 1)
        force_no_zero |= getExtruderNozzleCountTotal(preset_bundle, 1 - extruder_id) == 0;

-    ManualNozzleCountDialog dialog(wxGetApp().plater(), volume_type, standard_count, highflow_count, max_nozzle_count->values[extruder_id], force_no_zero);
+    // The printer profile's variant list is the authority on which volume types an extruder provides. An
+    // empty set means the profile could not be read, and the dialog then skips filtering instead of hiding
+    // everything.
+    const std::set<NozzleVolumeType> supported_types =
+        get_extruder_supported_nozzle_volume_types(preset_bundle->printers.get_edited_preset().config, extruder_id);
+
+    ManualNozzleCountDialog dialog(wxGetApp().plater(), volume_type, standard_count, highflow_count, e3d_count,
+                                   max_nozzle_count->values[extruder_id], force_no_zero, supported_types);
    if (dialog.ShowModal() == wxID_OK) {
        if (volume_type == nvtHybrid) {
            setExtruderNozzleCount(preset_bundle, extruder_id, nvtStandard, dialog.GetNozzleCount(nvtStandard), true);
            setExtruderNozzleCount(preset_bundle, extruder_id, nvtHighFlow, dialog.GetNozzleCount(nvtHighFlow), false);
+            setExtruderNozzleCount(preset_bundle, extruder_id, nvtE3DHighFlow, dialog.GetNozzleCount(nvtE3DHighFlow), false);
        } else {
            setExtruderNozzleCount(preset_bundle, extruder_id, volume_type, dialog.GetNozzleCount(volume_type), true);
        }
@@ -28,6 +28,7 @@

 #include <memory>
 #include <optional>
+#include <set>
 #include <unordered_map>
 #include <vector>

@@ -64,7 +65,9 @@ struct NozzleOption
 class ManualNozzleCountDialog : public DPIDialog
 {
 public:
-    ManualNozzleCountDialog(wxWindow *parent, NozzleVolumeType volume_type, int standard_count, int highflow_count, int max_nozzle_count, bool force_no_zero);
+    // supported_types lists the volume types the extruder physically provides; an empty set means "unknown", in which case no filtering is applied.
+    ManualNozzleCountDialog(wxWindow *parent, NozzleVolumeType volume_type, int standard_count, int highflow_count, int e3d_count, int max_nozzle_count, bool force_no_zero,
+                            const std::set<NozzleVolumeType> &supported_types);
    ~ManualNozzleCountDialog() override = default;
    void on_dpi_changed(const wxRect &suggested_rect) override {}
    int  GetNozzleCount(NozzleVolumeType volume_type) const;
@@ -72,6 +75,7 @@ public:
 private:
    ComboBox        *m_standard_choice{nullptr};
    ComboBox        *m_highflow_choice{nullptr};
+    ComboBox        *m_e3d_choice{nullptr};
    Button          *m_confirm_btn{nullptr};
    wxStaticText    *m_error_label{nullptr};
 };
@@ -4,6 +4,8 @@
 #include "StaticBox.hpp"

 #include "../wxExtensions.hpp"
+
+#include <wx/settings.h>
 #include "../GUI_App.hpp"
 #include "slic3r/GUI/I18N.hpp"
 #include "../Utils/MacDarkMode.hpp"
@@ -620,19 +622,34 @@ MultiSwitchButton::MultiSwitchButton(wxWindow *parent, wxWindowID id, const wxPo
          std::make_pair(0x6B6B6B, (int) StateColor::NotChecked),
          std::make_pair(0xFFFFFE, (int) StateColor::Normal)))
    , m_button_radius(10.0)
-    , m_button_padding(10, 6)
+    , m_button_padding(FromDIP(wxSize(11, 3)))
 {
    SetCornerRadius(m_button_radius);
    SetBorderWidth(0);

-    sizer = new wxBoxSizer(wxHORIZONTAL);
-    auto *hsizer = new wxBoxSizer(wxVERTICAL);
-    hsizer->Add(sizer, 1, wxEXPAND);
-    SetSizer(hsizer);
-    SetMinSize(wxSize(-1, 20));
+    // Orca: a switch can hold more buttons than the layout has room for (a toolchanger lists one per
+    // tool), so they live in a scrolled area: the caller caps the switch at its natural width and
+    // this scrolls horizontally instead of clipping the last buttons.
+    m_scroll = new wxScrolledWindow(this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxHSCROLL | wxBORDER_NONE);
+    m_scroll->SetBackgroundColour(GetBackgroundColour());
+    // The buttons are a single row, so only the horizontal bar may ever appear: a vertical one would
+    // eat into the row's height.
+    m_scroll->ShowScrollbars(wxSHOW_SB_DEFAULT, wxSHOW_SB_NEVER);
+    m_scroll->EnableScrolling(true, false);
+    m_scroll->SetScrollRate(FromDIP(10), 0);

+    sizer = new wxBoxSizer(wxHORIZONTAL);
+    m_scroll->SetSizer(sizer);
+
+    auto *hsizer = new wxBoxSizer(wxVERTICAL);
+    hsizer->Add(m_scroll, 1, wxEXPAND);
+    SetSizer(hsizer);
+    SetMinSize(wxSize(-1, options_height()));
+
+    Bind(wxEVT_SIZE, &MultiSwitchButton::on_size, this);
    Bind(wxEVT_COMMAND_BUTTON_CLICKED, &MultiSwitchButton::button_clicked, this);
-    SetFont(Label::Body_12);
+    // The tags name a tool and its volume type only, so they stay compact.
+    SetFont(Label::Body_10);
 }

 MultiSwitchButton::~MultiSwitchButton()
@@ -640,10 +657,88 @@ MultiSwitchButton::~MultiSwitchButton()
    DeleteAllOptions();
 }

+int MultiSwitchButton::options_height() const
+{
+    // With no button to measure yet, keep the placeholder height the switch starts with.
+    return btns.empty() ? FromDIP(20) : btns.front()->GetMinSize().y;
+}
+
+void MultiSwitchButton::update_scroll_range()
+{
+    // The scrollbar range is measured against the virtual size, so it has to follow the buttons
+    // whenever their labels or count change.
+    m_scroll->InvalidateBestSize();
+    m_scroll->FitInside();
+
+    // A scrolled window reports its min size plus a scrollbar as its best size, never the width of
+    // the buttons it holds, so the layout has to be given that width explicitly. It is also the
+    // widest this switch wants to be: a row with less room squeezes it below this and it scrolls.
+    const wxSize content = sizer->CalcMin();
+    SetMinSize(wxSize(content.x, options_height() + scrollbar_height(content.x)));
+    SetMaxSize(m_fit_to_options ? wxSize(content.x, -1) : wxDefaultSize);
+    InvalidateBestSize();
+}
+
+int MultiSwitchButton::scrollbar_height(int options_width) const
+{
+    // The bar is drawn inside the switch, so while the buttons need more width than the row gave us
+    // the switch has to be taller by the bar's height, or the bar sits on top of the buttons.
+    const int width = GetClientSize().x;
+    if (width <= 0 || options_width <= width)
+        return 0;
+
+    const int bar = wxSystemSettings::GetMetric(wxSYS_HSCROLL_Y, this);
+    return bar > 0 ? bar : 0;
+}
+
+void MultiSwitchButton::on_size(wxSizeEvent &evt)
+{
+    evt.Skip();
+
+    // The row resized, so the buttons may now overflow it (or no longer fit in it) and the room the
+    // bar needs changed with that. Width does not depend on height, so this settles in one pass.
+    const int height = options_height() + scrollbar_height(sizer->CalcMin().x);
+    if (GetMinSize().y != height) {
+        SetMinSize(wxSize(GetMinSize().x, height));
+        // The switch sits in a row of this tab, and the tab in a panel that shares its height
+        // with the page view, so both have to lay out again for the taller row to get its room.
+        if (wxWindow *tab = GetParent()) {
+            tab->Layout();
+            if (wxWindow *panel = tab->GetParent())
+                panel->Layout();
+        }
+    }
+}
+
+void MultiSwitchButton::scroll_option_into_view(Button *btn)
+{
+    const int width  = m_scroll->GetClientSize().x;
+    const int view_x = m_scroll->GetViewStartPixels().x;
+    if (width <= 0)     // not laid out yet: there is no view to scroll
+        return;
+
+    const wxRect rect   = btn->GetRect();
+    const int    right  = rect.GetRight() + 1;
+    int          target = view_x;
+    if (rect.x < view_x)
+        target = rect.x;
+    else if (right > view_x + width)
+        target = right - width;
+
+    if (target == view_x)
+        return;
+
+    // Scroll() counts scroll units; round up so the whole button ends up inside the view rather
+    // than a few pixels short of it.
+    int step = 1;
+    m_scroll->GetScrollPixelsPerUnit(&step, nullptr);
+    m_scroll->Scroll((target + step - 1) / step, -1);
+}
+
 int MultiSwitchButton::AppendOption(const wxString &option, void *clientData)
 {
    Button *btn = new Button();
-    btn->Create(this, option, "", wxBORDER_NONE);
+    btn->Create(m_scroll, option, "", wxBORDER_NONE);
    btn->SetFont(GetFont());
    btn->SetBackgroundColor(m_bg_color);
    btn->SetTextColor(m_text_color);
@@ -654,9 +749,6 @@ int MultiSwitchButton::AppendOption(const wxString &option, void *clientData)
    btns.push_back(btn);
    sizer->Add(btn, 1, wxEXPAND | wxALIGN_CENTER_VERTICAL);

-    wxSize text_size = btn->GetTextExtent(option);
-    btn->SetMinSize(wxSize(text_size.x + m_button_padding.x * 2 + 6, -1));
-
    return int(btns.size()) - 1;
 }

@@ -666,6 +758,7 @@ void MultiSwitchButton::SetOptions(const std::vector<wxString> &options)
    for (const auto &option : options)
        AppendOption(option);

+    update_scroll_range();
    Layout();
    Refresh();
 }
@@ -700,6 +793,8 @@ void MultiSwitchButton::SetSelection(int index)
    sel = index;
    update_button_styles();
    send_selection_event();
+    // The selected button may be scrolled out of sight, e.g. when the tab restores the active tool.
+    scroll_option_into_view(btns[sel]);
    Refresh();
 }

@@ -718,6 +813,7 @@ void MultiSwitchButton::SetOptionText(unsigned int index, const wxString &text)
    if (index >= btns.size())
        return;
    btns[index]->SetLabel(text);
+    update_scroll_range();
 }

 void *MultiSwitchButton::GetOptionData(unsigned int index) const
@@ -769,6 +865,7 @@ void MultiSwitchButton::SetButtonPadding(const wxSize &padding)
    m_button_padding = padding;
    for (auto *btn : btns)
        btn->SetPaddingSize(padding);
+    update_scroll_range();
    Layout();
    Refresh();
 }
@@ -777,6 +874,8 @@ void MultiSwitchButton::Rescale()
 {
    for (auto *btn : btns)
        btn->Rescale();
+    // Rescaling can change how the labels measure, and the scrollbar range follows the buttons.
+    update_scroll_range();
 }

 void MultiSwitchButton::button_clicked(wxCommandEvent &event)
@@ -7,6 +7,7 @@

 #include <vector>
 #include <wx/sizer.h>
+#include <wx/scrolwin.h>
 #include <wx/tglbtn.h>
 #include "Button.hpp"

@@ -164,6 +165,10 @@ public:
    void SetButtonCornerRadius(double radius);
    void SetButtonPadding(const wxSize &padding);

+    // Keep the switch exactly as wide as the buttons need instead of letting the layout stretch it.
+    // A layout with less room than that still squeezes it, and it scrolls its buttons then.
+    void SetFitToOptions(bool fit = true) { m_fit_to_options = fit; update_scroll_range(); }
+
    void Rescale();

 protected:
@@ -173,9 +178,20 @@ protected:
    bool send_selection_event();

 private:
+    // Height of the single button row, measured from the buttons themselves.
+    int  options_height() const;
+    void update_scroll_range();
+    int  scrollbar_height(int options_width) const;
+    void scroll_option_into_view(Button *btn);
+    void on_size(wxSizeEvent &evt);
+
    std::vector<Button *> btns;
-    wxBoxSizer           *sizer = nullptr;
-    int                   sel   = -1;
+    // The buttons are laid out inside this scrolled area so that a switch holding more options than
+    // the layout has room for scrolls instead of clipping its tail.
+    wxScrolledWindow     *m_scroll         = nullptr;
+    wxBoxSizer           *sizer            = nullptr;
+    bool                  m_fit_to_options = false;
+    int                   sel              = -1;

    StateColor m_bg_color;
    StateColor m_text_color;
@@ -106,6 +106,8 @@ wxString get_nozzle_volume_type_name(NozzleVolumeType type)
        return _L("Hybrid");
    } else if (NozzleVolumeType::nvtTPUHighFlow == type) {
        return _L("TPU High Flow");
+    } else if (NozzleVolumeType::nvtE3DHighFlow == type) {
+        return _L("E3D High Flow");
    }
    return wxString();
 }
@@ -715,3 +715,56 @@ TEST_CASE("Multi-extruder slice stays in bounds with a short max_layer_height",
    REQUIRE_FALSE(print.objects().front()->layers().empty());
 }

+
+// A filament can define several variants (Standard, High Flow). Each filament prints with its
+// variant of the extruder's variant string, or with its own first variant when it defines none, on a
+// printer listing a single variant as on one listing several.
+TEST_CASE("Each filament prints with its variant of the extruder's variant string", "[MultiFilament]")
+{
+    auto [variant_list, nozzle_volume_type, filament, temperature, resolved] = GENERATE(table<std::string, NozzleVolumeType, int, int, std::string>({
+        { "Direct Drive Standard",                        nvtStandard, 1, 211, "211,223" },
+        { "Direct Drive Standard",                        nvtStandard, 2, 223, "211,223" },
+        { "Direct Drive High Flow",                       nvtHighFlow, 1, 239, "239,223" },
+        { "Direct Drive High Flow",                       nvtHighFlow, 2, 223, "239,223" }, // filament 2 defines no High Flow variant
+        { "Direct Drive Standard,Direct Drive High Flow", nvtHighFlow, 1, 239, "239,223" },
+        { "Direct Drive Standard,Direct Drive High Flow", nvtHighFlow, 2, 223, "239,223" },
+    }));
+    DYNAMIC_SECTION(variant_list << " printer, " << get_nozzle_volume_type_string(nozzle_volume_type) << " nozzle, filament " << filament) {
+        DynamicPrintConfig config = multifilament_config(2, {
+            { "extruder_variant_list",            variant_list },
+            // filament 1 defines Standard (211) and High Flow (239), filament 2 Standard (223)
+            { "filament_extruder_variant",        "Direct Drive Standard;Direct Drive High Flow;Direct Drive Standard" },
+            { "filament_self_index",              "1,1,2" },
+            { "nozzle_temperature",               "211,239,223" },
+            { "nozzle_temperature_initial_layer", "211,239,223" },
+            { "sparse_infill_filament_id",        filament },
+            { "internal_solid_filament_id",       filament },
+            { "top_surface_filament_id",          filament },
+            { "bottom_surface_filament_id",       filament },
+            { "outer_wall_filament_id",           filament },
+            { "inner_wall_filament_id",           filament },
+            { "enable_prime_tower",               0 },
+            { "skirt_loops",                      0 },
+            { "brim_type",                        "no_brim" },
+            // custom G-code indexes the per-filament arrays by filament
+            { "machine_start_gcode",              "; start temperature {nozzle_temperature_initial_layer[initial_extruder]}" },
+        });
+        config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type", true)->values = { nozzle_volume_type };
+        const std::string gcode = slice({ cube(20) }, config);
+
+        std::set<int> temperatures;
+        std::istringstream stream(gcode);
+        for (std::string line; std::getline(stream, line);) {
+            if (line.rfind("M104 ", 0) != 0 && line.rfind("M109 ", 0) != 0)
+                continue;
+            const size_t s = line.find(" S");
+            if (s != std::string::npos && std::stoi(line.substr(s + 2)) > 0)
+                temperatures.insert(std::stoi(line.substr(s + 2)));
+        }
+        CHECK(temperatures == std::set<int>{ temperature });
+        CHECK(gcode.find("; start temperature " + std::to_string(temperature) + "\n") != std::string::npos);
+        // The config the slice ran with holds one value per filament, as the readers that index
+        // it by filament (the wipe tower, the filament compatibility check) expect.
+        CHECK(gcode.find("; nozzle_temperature = " + resolved + "\n") != std::string::npos);
+    }
+}
@@ -120,13 +120,25 @@ TEST_CASE("get_config_index_base resolves (volume type, extruder type, id) to a
        REQUIRE(get_config_index_base(nvtHighFlow, etDirectDrive, 2, variant_list, variant_ids) == 3);
    }

-    SECTION("no matching column falls back to slot 0") {
-        REQUIRE(get_config_index_base(nvtStandard, etDirectDrive, 3, variant_list, variant_ids) == 0);
+    SECTION("no matching variant falls back to the id's first variant") {
        REQUIRE(get_config_index_base(nvtStandard, etBowden, 1, variant_list, variant_ids) == 0);
+        REQUIRE(get_config_index_base(nvtStandard, etBowden, 2, variant_list, variant_ids) == 2);
    }

-    SECTION("Hybrid is not a preset variant string and falls back to slot 0") {
-        REQUIRE(get_config_index_base(nvtHybrid, etDirectDrive, 2, variant_list, variant_ids) == 0);
+    SECTION("an id without any variant falls back to variant index 0") {
+        REQUIRE(get_config_index_base(nvtStandard, etDirectDrive, 3, variant_list, variant_ids) == 0);
+    }
+
+    SECTION("Hybrid is not a preset variant string and falls back to the id's first variant") {
+        REQUIRE(get_config_index_base(nvtHybrid, etDirectDrive, 2, variant_list, variant_ids) == 2);
+    }
+
+    SECTION("a filament without a High Flow variant keeps its own variant, not the first filament's") {
+        // filament 1 defines Standard and High Flow, filament 2 only Standard
+        const std::vector<std::string> mixed_list = {"Direct Drive Standard", "Direct Drive High Flow", "Direct Drive Standard"};
+        const std::vector<int>         mixed_ids  = {1, 1, 2};
+        REQUIRE(get_config_index_base(nvtHighFlow, etDirectDrive, 1, mixed_list, mixed_ids) == 1);
+        REQUIRE(get_config_index_base(nvtHighFlow, etDirectDrive, 2, mixed_list, mixed_ids) == 2);
    }
 }

@@ -512,6 +524,73 @@ TEST_CASE("update_values_to_printer_extruders_for_multiple_filaments resolves pe
                     Catch::Matchers::Approx(std::vector<double>({-1., -1.})));
        REQUIRE(config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->values == std::vector<double>({12., 21.}));
    }
+
+    // A single extruder whose only variant is Standard or High Flow; filament 1 defines both
+    // variants, filament 2 only Standard.
+    auto make_single_variant_config = [](NozzleVolumeType nozzle_volume_type, const std::string &variant) {
+        DynamicPrintConfig config;
+        config.option<ConfigOptionEnumsGeneric>("extruder_type", true)->values = {etDirectDrive};
+        config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type", true)->values = {nozzle_volume_type};
+        config.option<ConfigOptionStrings>("extruder_variant_list", true)->values = {variant};
+        config.option<ConfigOptionFloats>("filament_diameter", true)->values = {1.75, 1.75};
+        config.option<ConfigOptionInts>("filament_self_index", true)->values = {1, 1, 2};
+        config.option<ConfigOptionStrings>("filament_extruder_variant", true)->values = {"Direct Drive Standard", "Direct Drive High Flow",
+                                                                                         "Direct Drive Standard"};
+        config.option<ConfigOptionFloats>("filament_max_volumetric_speed", true)->values = {12., 20., 13.};
+        config.option<ConfigOptionInts>("filament_map", true)->values = {1, 1};
+        return config;
+    };
+
+    SECTION("a single-variant printer picks each filament's variant of that variant string") {
+        auto [nozzle_volume_type, variant, speeds] = GENERATE(table<NozzleVolumeType, std::string, std::vector<double>>({
+            {nvtStandard, "Direct Drive Standard", {12., 13.}},
+            // filament 2 defines no High Flow variant and keeps its first
+            {nvtHighFlow, "Direct Drive High Flow", {20., 13.}},
+        }));
+        DynamicPrintConfig config = make_single_variant_config(nozzle_volume_type, variant);
+        int extruder_count = 1;
+        REQUIRE_FALSE(config.support_different_extruders(extruder_count));
+        REQUIRE(config.has_multi_variant_filament());
+
+        std::vector<std::vector<NozzleVolumeType>> nozzle_volume_types;
+        int count = config.get_extruder_nozzle_volume_count(extruder_count, nozzle_volume_types);
+        config.update_values_to_printer_extruders_for_multiple_filaments(config, extruder_count, count, filament_keys,
+            "filament_self_index", "filament_extruder_variant");
+
+        REQUIRE(config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->values == speeds);
+        REQUIRE(config.option<ConfigOptionInts>("filament_self_index")->values == std::vector<int>({1, 2}));
+    }
+
+    SECTION("a filament map shorter than the filament count keeps every filament") {
+        DynamicPrintConfig config = make_single_variant_config(nvtStandard, "Direct Drive Standard");
+        config.option<ConfigOptionInts>("filament_map", true)->values = {1};
+
+        std::vector<std::vector<NozzleVolumeType>> nozzle_volume_types;
+        int extruder_count = 1;
+        int count = config.get_extruder_nozzle_volume_count(extruder_count, nozzle_volume_types);
+        config.update_values_to_printer_extruders_for_multiple_filaments(config, extruder_count, count, filament_keys,
+            "filament_self_index", "filament_extruder_variant");
+
+        REQUIRE(config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->values == std::vector<double>({12., 13.}));
+        REQUIRE(config.option<ConfigOptionInts>("filament_self_index")->values == std::vector<int>({1, 2}));
+    }
+}
+
+TEST_CASE("has_multi_variant_filament is true only when a filament defines more than one variant", "[Config]")
+{
+    DynamicPrintConfig config;
+    config.option<ConfigOptionFloats>("filament_diameter", true)->values = {1.75, 1.75};
+
+    SECTION("one variant per filament reports false") {
+        config.option<ConfigOptionStrings>("filament_extruder_variant", true)->values = {"Direct Drive Standard", "Bowden Standard"};
+        REQUIRE_FALSE(config.has_multi_variant_filament());
+    }
+
+    SECTION("a filament with Standard and High Flow variants reports true") {
+        config.option<ConfigOptionStrings>("filament_extruder_variant", true)->values = {"Direct Drive Standard", "Direct Drive High Flow",
+                                                                                         "Direct Drive Standard"};
+        REQUIRE(config.has_multi_variant_filament());
+    }
 }

 // update_values_from_multi_to_multi_2 walks the DESTINATION PRINTER's variant list while writing
@@ -10,11 +10,13 @@ TEST_CASE("convert_to_nvt_type maps extruder variant strings to nozzle volume ty
        REQUIRE(convert_to_nvt_type("Direct Drive Standard") == nvtStandard);
        REQUIRE(convert_to_nvt_type("Direct Drive High Flow") == nvtHighFlow);
        REQUIRE(convert_to_nvt_type("Direct Drive TPU High Flow") == nvtTPUHighFlow);
+        REQUIRE(convert_to_nvt_type("Direct Drive E3D High Flow") == nvtE3DHighFlow);
    }

    SECTION("Bowden variants") {
        REQUIRE(convert_to_nvt_type("Bowden Standard") == nvtStandard);
        REQUIRE(convert_to_nvt_type("Bowden High Flow") == nvtHighFlow);
+        REQUIRE(convert_to_nvt_type("Bowden E3D High Flow") == nvtE3DHighFlow);
    }

    SECTION("Unparsable strings fall back to hybrid") {
@@ -29,3 +31,49 @@ TEST_CASE("convert_to_nvt_type maps extruder variant strings to nozzle volume ty
        REQUIRE(convert_to_nvt_type(" Bowden Standard") == nvtStandard);
    }
 }
+
+TEST_CASE("E3D High Flow is nozzle volume type 5, after the reserved 4", "[Config]")
+{
+    REQUIRE(int(nvtE3DHighFlow) == 5);
+    REQUIRE(get_valid_nozzle_volume_type() == std::set<NozzleVolumeType>{nvtStandard, nvtHighFlow, nvtTPUHighFlow, nvtE3DHighFlow});
+    REQUIRE(get_nozzle_volume_type_string(nvtE3DHighFlow) == "E3D High Flow");
+    REQUIRE(get_extruder_variant_string(etDirectDrive, nvtE3DHighFlow) == "Direct Drive E3D High Flow");
+    REQUIRE(get_extruder_variant_string(etBowden, nvtE3DHighFlow) == "Bowden E3D High Flow");
+
+    SECTION("nozzle_volume_type round-trips it by name") {
+        DynamicPrintConfig config;
+        config.set_deserialize_strict("nozzle_volume_type", "Standard,E3D High Flow");
+        REQUIRE(config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type")->values == std::vector<int>{nvtStandard, nvtE3DHighFlow});
+        REQUIRE(config.opt_serialize("nozzle_volume_type") == "Standard,E3D High Flow");
+    }
+
+    SECTION("its variant is found by value, not mistaken for High Flow") {
+        const std::vector<std::string> variant_list = {"Direct Drive Standard", "Direct Drive High Flow", "Direct Drive E3D High Flow"};
+        const std::vector<int>         variant_ids  = {1, 1, 1};
+        REQUIRE(get_config_index_base(nvtE3DHighFlow, etDirectDrive, 1, variant_list, variant_ids) == 2);
+        REQUIRE(get_config_index_base(nvtHighFlow, etDirectDrive, 1, variant_list, variant_ids) == 1);
+    }
+}
+
+TEST_CASE("get_extruder_supported_nozzle_volume_types reads the extruder's variant list", "[Config]")
+{
+    DynamicPrintConfig config;
+    // H2C: the left extruder offers E3D High Flow, the right (nozzle rack) extruder does not.
+    config.set_deserialize_strict("extruder_type", "Direct Drive,Direct Drive");
+    config.option<ConfigOptionStrings>("extruder_variant_list", true)->values = {
+        "Direct Drive Standard,Direct Drive High Flow,Direct Drive E3D High Flow",
+        "Direct Drive Standard,Direct Drive High Flow"};
+
+    REQUIRE(get_extruder_supported_nozzle_volume_types(config, 0) == std::set<NozzleVolumeType>{nvtStandard, nvtHighFlow, nvtE3DHighFlow});
+    REQUIRE(get_extruder_supported_nozzle_volume_types(config, 1) == std::set<NozzleVolumeType>{nvtStandard, nvtHighFlow});
+
+    SECTION("an E3D-only list does not report plain High Flow") {
+        config.option<ConfigOptionStrings>("extruder_variant_list")->values[1] = "Direct Drive Standard,Direct Drive E3D High Flow";
+        REQUIRE(get_extruder_supported_nozzle_volume_types(config, 1) == std::set<NozzleVolumeType>{nvtStandard, nvtE3DHighFlow});
+    }
+
+    SECTION("an extruder past the profile's lists gives the empty, unknown set") {
+        REQUIRE(get_extruder_supported_nozzle_volume_types(config, 2).empty());
+        REQUIRE(get_extruder_supported_nozzle_volume_types(config, -1).empty());
+    }
+}