diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index f5b0d1c713..3ca75d28f3 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -161,11 +161,18 @@ void extend_default_config_length(DynamicPrintConfig& config, const bool set_nil
     int process_variant_length = default_param_length;
     int machine_variant_length = default_param_length;
 
+    // Orca: use nozzle/extruder count as the default printer variant length
+    // because non-BBL multi-extruder printers currently do not support extruder variant.
+    if (config.has("nozzle_diameter")) {
+        auto* nozzle_diameter = dynamic_cast<const ConfigOptionFloats*>(config.option("nozzle_diameter"));
+        machine_variant_length = nozzle_diameter->values.size();
+    }
+
     if(config.has("filament_extruder_variant"))
         filament_variant_length = config.option<ConfigOptionStrings>("filament_extruder_variant")->size();
     if(config.has("print_extruder_variant"))
         process_variant_length = config.option<ConfigOptionStrings>("print_extruder_variant")->size();
-    if(config.has("printer_extruder_variant"))
+    if(config.has("printer_extruder_variant"))  // Use existing variant list if specified, so BBL's multi-variant profiles still works
         machine_variant_length = config.option<ConfigOptionStrings>("printer_extruder_variant")->size();
 
     auto replace_nil_and_resize = [&](const std::string & key, int length){
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 3e48103915..6287e77ceb 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -7996,8 +7996,41 @@ size_t DynamicPrintConfig::get_parameter_size(const std::string& param_name, siz
     return extruder_nums;
 }
 
+// Orca: Special handling for extruder variants
+// BBL printers have extruder variants pre-defined in system profiles, however for customized multi-extruder profile,
+// we need to set up these parameters automatically, otherwise per-extruder options won't work properly.
+static void extend_extruder_variant(DynamicPrintConfig& config, const unsigned int num_extruders)
+{
+    // 1. Make sure the `extruder_variant_list` is the same length as extruder cnt
+    auto extruder_variant_opt = dynamic_cast<ConfigOptionStrings*>(config.option("extruder_variant_list"));
+    assert(extruder_variant_opt != nullptr);
+    extruder_variant_opt->resize(num_extruders, extruder_variant_opt); // Use the first option as the default value, so all extruders have the same variant
+
+    // 2. Update `printer_extruder_variant` and `printer_extruder_id` based on `extruder_variant_list`
+    auto printer_extruder_id_opt = dynamic_cast<ConfigOptionInts*>(config.option("printer_extruder_id"));
+    assert(printer_extruder_id_opt != nullptr);
+    printer_extruder_id_opt->values.clear();
+    auto printer_extruder_variant_opt = dynamic_cast<ConfigOptionStrings*>(config.option("printer_extruder_variant"));
+    assert(printer_extruder_variant_opt != nullptr);
+    printer_extruder_variant_opt->values.clear();
+    for (int i = 0; i < num_extruders; i++) {
+        // `extruder_variant_list` specifies supported variant of each nozzle/extruder,
+        // each item is a comma separated list of variants (extruder type + nozzle flow type) this extruder supported
+        std::string variant = extruder_variant_opt->get_at(i);
+        std::vector<std::string> variants_list;
+        boost::split(variants_list, variant, boost::is_any_of(","), boost::token_compress_on);
+
+        if (!variants_list.empty()) {
+            printer_extruder_id_opt->values.insert(printer_extruder_id_opt->values.end(), variants_list.size(), i + 1);
+            printer_extruder_variant_opt->values.insert(printer_extruder_variant_opt->values.end(), variants_list.begin(), variants_list.end());
+        }
+    }
+}
+
 void DynamicPrintConfig::set_num_extruders(unsigned int num_extruders)
 {
+    extend_extruder_variant(*this, num_extruders);
+
     const auto &defaults = FullPrintConfig::defaults();
     for (const std::string &key : print_config_def.extruder_option_keys()) {
         if (key == "default_filament_profile")
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 377ae13c3f..1f3d73751b 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -1914,7 +1914,9 @@ void Tab::on_value_change(const std::string& opt_key, const boost::any& value)
         }
     }
 
-    if (m_preset_bundle->get_printer_extruder_count() > 1){
+    // Orca: allow different layer height for non-bbl printers
+    // TODO: allow this for BBL printers too?
+    if (m_preset_bundle->get_printer_extruder_count() > 1 && m_preset_bundle->is_bbl_vendor()) {
         int extruder_idx = std::atoi(opt_key.substr(opt_key.find_last_of('#') + 1).c_str());
         if (opt_key.find("min_layer_height") != std::string::npos) {
             auto min_layer_height_from_nozzle = m_preset_bundle->full_config().option<ConfigOptionFloats>("min_layer_height")->values;