diff --git a/resources/web/dialog/PluginsConfigDialog/index.html b/resources/web/dialog/PluginsConfigDialog/index.html
index 8e44bac35d..6ce4d29dcc 100644
--- a/resources/web/dialog/PluginsConfigDialog/index.html
+++ b/resources/web/dialog/PluginsConfigDialog/index.html
@@ -48,6 +48,7 @@
       <span id="statusText" class="status-text"></span>
     </footer>
   </main>
+  <script src="../js/plugin-config-ui.js"></script>
   <script src="index.js"></script>
 </body>
 </html>
diff --git a/resources/web/dialog/PluginsConfigDialog/index.js b/resources/web/dialog/PluginsConfigDialog/index.js
index 013ec7ac16..3df85e0a33 100644
--- a/resources/web/dialog/PluginsConfigDialog/index.js
+++ b/resources/web/dialog/PluginsConfigDialog/index.js
@@ -9,6 +9,11 @@ let selectedCapabilityType = "";
 let selectedHasPresetOverride = false;
 let selectedReadOnly = false;
 
+// Identity of the capability whose custom UI is currently loaded in the frame. Saving re-sends the
+// whole capability_config payload, and rebuilding the frame from it would reload the plugin's page
+// under the user's cursor; when this still matches, the new values are posted in instead.
+let customFrameKey = "";
+
 function SafeJsonParse(text) {
   try {
     return JSON.parse(text);
@@ -168,6 +173,10 @@ function IsCurrentCapability(payload) {
     && String(payload?.capability_type || "") === selectedCapabilityType;
 }
 
+function CapabilityKey(payload) {
+  return JSON.stringify([payload?.plugin_key, payload?.capability_name, payload?.capability_type]);
+}
+
 function RequestCapabilityConfig() {
   if (!selectedPluginKey || !selectedCapabilityName)
     return;
@@ -193,6 +202,7 @@ function ClearCapabilityConfigView() {
   if (custom) {
     custom.hidden = true;
     custom.removeAttribute("srcdoc");
+    customFrameKey = "";
   }
   if (text)
     text.value = "";
@@ -248,8 +258,14 @@ function ApplyCapabilityConfig(payload) {
 
   if (html) {
     if (custom) {
+      const context = OrcaConfigContext(payload, "preset");
       custom.hidden = false;
-      custom.srcdoc = BuildCustomConfigDocument(html, config);
+      if (customFrameKey === CapabilityKey(payload) && custom.contentWindow) {
+        custom.contentWindow.postMessage({ __orca: "config", config: config, context: context }, "*");
+      } else {
+        customFrameKey = CapabilityKey(payload);
+        custom.srcdoc = BuildCustomConfigDocument(html, config, context);
+      }
     }
     if (editor)
       editor.hidden = true;
@@ -260,6 +276,7 @@ function ApplyCapabilityConfig(payload) {
   if (custom) {
     custom.hidden = true;
     custom.removeAttribute("srcdoc");
+    customFrameKey = "";
   }
   if (editor)
     editor.hidden = false;
@@ -354,39 +371,6 @@ function ApplyCapabilityConfigSaved(payload) {
   SetConfigValidation("");
 }
 
-// The whole host surface a custom config UI gets: read the config, save one, drop the preset's
-// override, and be told when either lands. The frame is sandboxed into an opaque origin, so this
-// bridge is its only channel.
-function BuildCustomConfigDocument(html, config) {
-  // Inlined into a <script>: a stored "</script>" would close the tag early, so escape "<" — the
-  // literal stays valid JSON.
-  const seed = JSON.stringify(config).replace(/</g, "\\u003c");
-  const bridge = `<script>
-(function () {
-  var handlers = [];
-  var current = ${seed};
-  window.orca = {
-    getConfig: function () { return current; },
-    saveConfig: function (cfg) { parent.postMessage({ __orca: "save", config: cfg }, "*"); },
-    restoreDefaults: function () { parent.postMessage({ __orca: "restore" }, "*"); },
-    onConfig: function (cb) {
-      if (typeof cb !== "function") return;
-      handlers.push(cb);
-      try { cb(current); } catch (e) {}
-    }
-  };
-  window.addEventListener("message", function (event) {
-    if (!event.data || event.data.__orca !== "config") return;
-    current = event.data.config || {};
-    handlers.forEach(function (handler) {
-      try { handler(current); } catch (e) {}
-    });
-  });
-})();
-<\/script>`;
-  return bridge + html;
-}
-
 function OnCustomConfigMessage(event) {
   const custom = document.getElementById("configCustom");
   // Only the frame we created, and only while it is actually showing.
@@ -432,6 +416,7 @@ document.addEventListener("DOMContentLoaded", () => {
   // OnCustomConfigMessage matches on the frame's contentWindow, not the origin ("null" when
   // sandboxed), and ignores anything else.
   window.addEventListener("message", OnCustomConfigMessage);
+  OrcaWatchThemeForFrame(() => document.getElementById("configCustom"));
 
   SendMessage("request_capabilities");
 });
diff --git a/resources/web/dialog/PluginsDialog/index.html b/resources/web/dialog/PluginsDialog/index.html
index 1e879339ed..3cee806786 100644
--- a/resources/web/dialog/PluginsDialog/index.html
+++ b/resources/web/dialog/PluginsDialog/index.html
@@ -15,6 +15,7 @@
   <script type="text/javascript" src="../../data/text.js"></script>
   <script type="text/javascript" src="../js/globalapi.js"></script>
   <script type="text/javascript" src="../js/common.js"></script>
+  <script src="../js/plugin-config-ui.js"></script>
   <script src="./index.js"></script>
   <script src="./plugin-sort.js"></script>
   <script src="../js/fuzzy-search.js"></script>
diff --git a/resources/web/dialog/PluginsDialog/index.js b/resources/web/dialog/PluginsDialog/index.js
index cd690ef8b1..036fc8552a 100644
--- a/resources/web/dialog/PluginsDialog/index.js
+++ b/resources/web/dialog/PluginsDialog/index.js
@@ -90,6 +90,7 @@ function OnInit() {
   // OnCustomConfigMessage matches on the frame's contentWindow, not the origin ("null" when
   // sandboxed), and ignores anything else.
   window.addEventListener("message", OnCustomConfigMessage);
+  OrcaWatchThemeForFrame(() => document.getElementById("configCustom"));
 
   document.addEventListener("click", (event) => {
     if (!event.target.closest(".ctx"))
@@ -1077,7 +1078,7 @@ function ApplyCapabilityConfig(payload) {
   if (html) {
     if (custom) {
       custom.hidden = false;
-      custom.srcdoc = BuildCustomConfigDocument(html, config);
+      custom.srcdoc = BuildCustomConfigDocument(html, config, OrcaConfigContext(payload, "global"));
     }
     if (editor)
       editor.hidden = true;
@@ -1178,39 +1179,6 @@ function ApplyCapabilityConfigSaved(payload) {
   SetConfigValidation("");
 }
 
-// The whole host surface a custom config UI gets: read the config, save one, restore the plugin's
-// defaults, and be told when either lands. The frame is sandboxed into an opaque origin, so this
-// bridge is its only channel.
-function BuildCustomConfigDocument(html, config) {
-  // Inlined into a <script>: a stored "</script>" would close the tag early, so escape "<" — the
-  // literal stays valid JSON.
-  const seed = JSON.stringify(config).replace(/</g, "\\u003c");
-  const bridge = `<script>
-(function () {
-  var handlers = [];
-  var current = ${seed};
-  window.orca = {
-    getConfig: function () { return current; },
-    saveConfig: function (cfg) { parent.postMessage({ __orca: "save", config: cfg }, "*"); },
-    restoreDefaults: function () { parent.postMessage({ __orca: "restore" }, "*"); },
-    onConfig: function (cb) {
-      if (typeof cb !== "function") return;
-      handlers.push(cb);
-      try { cb(current); } catch (e) {}
-    }
-  };
-  window.addEventListener("message", function (event) {
-    if (!event.data || event.data.__orca !== "config") return;
-    current = event.data.config || {};
-    handlers.forEach(function (handler) {
-      try { handler(current); } catch (e) {}
-    });
-  });
-})();
-<\/script>`;
-  return bridge + html;
-}
-
 function OnCustomConfigMessage(event) {
   const custom = document.getElementById("configCustom");
   // Only the frame we created, and only while it is actually showing.
diff --git a/resources/web/dialog/js/plugin-config-ui.js b/resources/web/dialog/js/plugin-config-ui.js
new file mode 100644
index 0000000000..0f16c0c48c
--- /dev/null
+++ b/resources/web/dialog/js/plugin-config-ui.js
@@ -0,0 +1,130 @@
+// The host surface a plugin capability's custom configuration UI gets, shared by the Plugins dialog
+// and by a preset's plugin configuration dialog. Both host the page in an iframe sandboxed into an
+// opaque origin, so this bridge is its only channel, and both must offer plugin authors exactly the
+// same one — hence a single module rather than a copy per dialog.
+
+// The host theme "contract" (WebViewHostDialog::host_theme_vars_css). The document-start injector
+// stamps it on the top-level page only — it returns early in child frames — so a sandboxed config UI
+// never sees it unless we hand it over.
+const ORCA_THEME_VARS = [
+  "--orca-bg",
+  "--orca-fg",
+  "--orca-muted",
+  "--orca-border",
+  "--orca-accent",
+  "--orca-accent-fg",
+  "--orca-font"
+];
+
+// Read the contract off this page as it is rendering right now, so the frame always opens in the
+// live theme rather than whatever the app started in.
+function OrcaThemeSnapshot() {
+  const style = getComputedStyle(document.documentElement);
+  const vars = {};
+  ORCA_THEME_VARS.forEach((name) => {
+    // Values are host-produced colors and a pre-sanitized font stack; strip anything that could end
+    // the declaration or the <style> block it gets inlined into.
+    const value = String(style.getPropertyValue(name) || "").trim().replace(/[<>{};]/g, "");
+    if (value)
+      vars[name] = value;
+  });
+  return {
+    theme: document.documentElement.getAttribute("data-orca-theme") === "dark" ? "dark" : "light",
+    vars: vars
+  };
+}
+
+// Inlined into a <script> or a JSON payload: a stored "</script>" would close the tag early, so
+// escape "<" — the literal stays valid JSON.
+function OrcaInlineJson(value) {
+  return JSON.stringify(value === undefined ? null : value).replace(/</g, "\\u003c");
+}
+
+// What a custom UI can learn about the surface it is being edited on. Kept to what changes the
+// page's own behavior: "Restore defaults" writes the plugin's get_default_config() in the Plugins
+// dialog but drops the preset's override in a preset dialog, so a page cannot label its own button
+// without knowing the scope.
+function OrcaConfigContext(payload, scope) {
+  return {
+    scope: scope,
+    readOnly: payload ? payload.read_only === true : false,
+    hasPresetOverride: payload ? payload.has_preset_override === true : false
+  };
+}
+
+// The whole host surface: read the config, save one, restore defaults, follow the theme, and be told
+// when any of it lands.
+function BuildCustomConfigDocument(html, config, context) {
+  const theme = OrcaThemeSnapshot();
+  const bridge = `<style id="orca-host-theme-vars"></style>
+<script>
+(function () {
+  var handlers = [];
+  var themeHandlers = [];
+  var current = ${OrcaInlineJson(config === undefined ? {} : config)};
+  var context = ${OrcaInlineJson(context || {})};
+  var theme = ${OrcaInlineJson(theme)};
+
+  function applyTheme(next) {
+    if (next && next.vars) theme = next;
+    var css = ":root{";
+    for (var name in theme.vars)
+      if (Object.prototype.hasOwnProperty.call(theme.vars, name)) css += name + ":" + theme.vars[name] + ";";
+    css += "color-scheme:" + theme.theme + ";}";
+    var style = document.getElementById("orca-host-theme-vars");
+    if (style) style.textContent = css;
+    if (document.documentElement) document.documentElement.setAttribute("data-orca-theme", theme.theme);
+    themeHandlers.forEach(function (handler) {
+      try { handler(theme.theme); } catch (e) {}
+    });
+  }
+
+  window.orca = {
+    getConfig: function () { return current; },
+    saveConfig: function (cfg) { parent.postMessage({ __orca: "save", config: cfg }, "*"); },
+    restoreDefaults: function () { parent.postMessage({ __orca: "restore" }, "*"); },
+    getContext: function () { return context; },
+    onConfig: function (cb) {
+      if (typeof cb !== "function") return;
+      handlers.push(cb);
+      try { cb(current); } catch (e) {}
+    },
+    onTheme: function (cb) {
+      if (typeof cb !== "function") return;
+      themeHandlers.push(cb);
+      try { cb(theme.theme); } catch (e) {}
+    }
+  };
+
+  window.addEventListener("message", function (event) {
+    if (!event.data) return;
+    if (event.data.__orca === "theme") { applyTheme(event.data.theme); return; }
+    if (event.data.__orca !== "config") return;
+    current = event.data.config || {};
+    if (event.data.context) context = event.data.context;
+    handlers.forEach(function (handler) {
+      try { handler(current); } catch (e) {}
+    });
+  });
+
+  applyTheme();
+})();
+<\/script>`;
+  return bridge + html;
+}
+
+// The host re-themes an open dialog in place (WebViewHostDialog::host_theme_apply_js rewrites the
+// injected variables and re-stamps data-orca-theme), which a sandboxed child frame never sees. Relay
+// it so a custom UI follows a light/dark switch without being reopened.
+function OrcaWatchThemeForFrame(getFrame) {
+  const relay = () => {
+    const frame = getFrame();
+    if (!frame || frame.hidden || !frame.contentWindow)
+      return;
+    frame.contentWindow.postMessage({ __orca: "theme", theme: OrcaThemeSnapshot() }, "*");
+  };
+  new MutationObserver(relay).observe(document.documentElement, {
+    attributes: true,
+    attributeFilter: ["data-orca-theme"]
+  });
+}
diff --git a/sandboxes/orca_twistify_plugin_example_any.py b/sandboxes/orca_twistify_plugin_example_any.py
index 4714af536b..031686abdf 100644
--- a/sandboxes/orca_twistify_plugin_example_any.py
+++ b/sandboxes/orca_twistify_plugin_example_any.py
@@ -5,7 +5,7 @@
 # name = "Twistify"
 # description = "Twists, tapers, and wobbles every layer's slice polygons as a function of Z (demo)."
 # author = "OrcaSlicer"
-# version = "0.02"
+# version = "0.03"
 # type = "slicing-pipeline"
 # ///
 """Twistify -- twist/taper/wobble any model at slice time.
@@ -25,8 +25,17 @@ preview corkscrews and the print keeps correct walls/infill/flow.
 Because we edit geometry in place, surface types are preserved automatically
 (no per-surface type carry needed), and no numpy is required --
 rotate/scale/translate are host methods. Parameters come from self.get_config()
-(see _params below), which the host seeds from get_default_config(). The first
-object layer is untouched (z_rel = 0), so bed adhesion is unaffected.
+(see _params below); the host seeds them from get_default_config() the first
+time the plugin loads. The first object layer is untouched (z_rel = 0), so bed
+adhesion is unaffected.
+
+The plugin also ships its own configuration UI (has_config_ui/get_config_ui):
+a self-contained page the Plugins dialog renders instead of the JSON editor,
+drawing the transform it is about to apply as an isometric stack of layer
+outlines. It reaches the host only through the injected window.orca bridge --
+getConfig/saveConfig/restoreDefaults/getContext/onConfig/onTheme -- and styles
+itself from the --orca-* theme variables the host hands the frame, so it
+follows OrcaSlicer's light/dark theme.
 """
 import math
 import json
@@ -44,7 +53,7 @@ _DEFAULTS = {
 def _params(self):
     try:
         src = json.loads(self.get_config())
-    except (AttributeError, TypeError):
+    except (AttributeError, TypeError, ValueError):
         src = {}
     out = {}
     for key, default in _DEFAULTS.items():
@@ -69,13 +78,485 @@ def _layer_params(z_rel, mm_to_scaled, p):
     return theta, s, ox
 
 
+# The configuration page. Self-contained on purpose: it runs in an iframe sandboxed into an opaque
+# origin, so there is no network, no same-origin access to the host, and no shared stylesheet --
+# only the window.orca bridge and the --orca-* theme variables the host injects. __ORCA_DEFAULTS__
+# is substituted with _DEFAULTS in get_config_ui(), so Python stays the single source of truth for
+# the values; the page adds only presentation (ranges, labels, wording).
+_CONFIG_UI = """
+<style>
+  :root {
+    --ink:      var(--orca-fg, #1f2429);
+    --paper:    var(--orca-bg, #ffffff);
+    --rule:     var(--orca-border, #d9dee3);
+    --quiet:    var(--orca-muted, #6b7580);
+    --live:     var(--orca-accent, #009688);
+    --live-ink: var(--orca-accent-fg, #ffffff);
+    --ui:       var(--orca-font, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif);
+    --data:     ui-monospace, "Cascadia Mono", "SF Mono", Menlo, Consolas, monospace;
+  }
+  @media (prefers-color-scheme: dark) {
+    :root {
+      --ink:   var(--orca-fg, #e4e6e8);
+      --paper: var(--orca-bg, #2b2d30);
+      --rule:  var(--orca-border, #3d4043);
+      --quiet: var(--orca-muted, #9aa0a6);
+    }
+  }
+
+  * { box-sizing: border-box; }
+  html, body { height: 100%; }
+  body {
+    margin: 0;
+    background: var(--paper);
+    color: var(--ink);
+    font: 13px/1.45 var(--ui);
+  }
+  .panel { display: flex; flex-direction: column; height: 100%; }
+
+  .head {
+    display: flex; align-items: baseline; gap: 10px;
+    padding: 12px 16px 10px;
+    border-bottom: 1px solid var(--rule);
+  }
+  .mark {
+    font: 10px/1 var(--data); letter-spacing: .14em; text-transform: uppercase;
+    color: var(--live);
+  }
+  .head-note { font-size: 11px; color: var(--quiet); }
+
+  /* The frame is as narrow as ~400px in a resized dialog and as wide as ~600px; below the
+     breakpoint the drawing moves under the controls rather than squeezing both. */
+  .work {
+    flex: 1; min-height: 0; overflow: auto;
+    display: grid; grid-template-columns: minmax(0, 1fr) 180px; gap: 16px;
+    align-content: start; padding: 14px 16px;
+  }
+  @media (max-width: 470px) {
+    .work { grid-template-columns: minmax(0, 1fr); }
+    .plot { max-width: 210px; }
+  }
+
+  .rows { display: flex; flex-direction: column; gap: 12px; }
+  .row { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 4px 8px; }
+  .row-label {
+    grid-column: 1;
+    font: 10px/1 var(--data); letter-spacing: .12em; text-transform: uppercase;
+    color: var(--quiet);
+  }
+  .row-figure { grid-column: 2; display: flex; align-items: baseline; gap: 4px; }
+  .row-figure input {
+    /* No spinners: the rail is the coarse control, this is the exact one, and the arrows would
+       steal the width the value needs. */
+    -webkit-appearance: textfield; appearance: textfield;
+    width: 76px; padding: 3px 6px; text-align: right;
+    font: 13px/1.2 var(--data); font-variant-numeric: tabular-nums;
+    color: var(--ink); background: transparent;
+    border: 1px solid transparent; border-radius: 3px;
+  }
+  .row-figure input::-webkit-outer-spin-button,
+  .row-figure input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
+  .row-figure input:hover { border-color: var(--rule); }
+  .row-figure input:focus { outline: none; border-color: var(--live); }
+  .unit { font: 10px/1 var(--data); color: var(--quiet); min-width: 26px; }
+
+  /* The rail carries a detent at the value that means "no deformation", so neutral is a position
+     you can feel for rather than a number you have to read. */
+  .rail { grid-column: 1 / -1; position: relative; height: 16px; }
+  .rail[data-detent]::before {
+    content: ""; position: absolute; left: var(--detent); top: 3px;
+    width: 1px; height: 10px; background: var(--rule);
+  }
+  .rail input {
+    -webkit-appearance: none; appearance: none;
+    position: relative; width: 100%; height: 16px; margin: 0; background: transparent;
+  }
+  .rail input::-webkit-slider-runnable-track { height: 2px; background: var(--rule); border-radius: 1px; }
+  .rail input::-webkit-slider-thumb {
+    -webkit-appearance: none; width: 11px; height: 11px; margin-top: -4.5px;
+    border: none; border-radius: 50%; background: var(--live); cursor: grab;
+  }
+  .rail input:focus { outline: none; }
+  .rail input:focus-visible { outline: 2px solid var(--live); outline-offset: 1px; border-radius: 3px; }
+  .rail input:disabled::-webkit-slider-thumb { background: var(--quiet); cursor: default; }
+
+  .readout {
+    margin-top: 14px; padding-top: 10px; border-top: 1px solid var(--rule);
+    font-size: 11px; color: var(--quiet); min-height: 32px;
+  }
+  .readout b { color: var(--ink); font-weight: 600; font-family: var(--data); font-variant-numeric: tabular-nums; }
+
+  .plot { margin: 0; display: flex; flex-direction: column; gap: 6px; }
+  .plot svg { width: 100%; height: auto; display: block; }
+  .plot figcaption { font: 10px/1.4 var(--data); color: var(--quiet); }
+  /* SVG colours live here rather than in stroke="" attributes: var() is not reliable in a
+     presentation attribute, and this way the drawing re-themes with the rest of the page. */
+  .ring, .helix, .datum { fill: none; }
+  .ring  { stroke: var(--live); stroke-width: 1; }
+  .helix { stroke: var(--live); stroke-width: 1; stroke-opacity: .5; stroke-dasharray: 2 2; }
+  .datum { stroke: var(--quiet); stroke-width: 1; stroke-opacity: .7; }
+  .tick  { stroke: var(--rule); stroke-width: 1; }
+  .plot text { fill: var(--quiet); font: 8px var(--data); }
+
+  .foot {
+    display: flex; align-items: center; gap: 10px;
+    padding: 10px 16px; border-top: 1px solid var(--rule);
+  }
+  .state { flex: 1; font-size: 11px; color: var(--quiet); }
+  .state.dirty { color: var(--ink); }
+  button {
+    font: 12px/1 var(--ui); padding: 6px 14px; border-radius: 4px; cursor: pointer;
+    border: 1px solid var(--rule); background: transparent; color: var(--ink);
+  }
+  button.go { border-color: var(--live); background: var(--live); color: var(--live-ink); }
+  button:disabled { opacity: .45; cursor: default; }
+  button:focus-visible { outline: 2px solid var(--live); outline-offset: 2px; }
+
+  @media (prefers-reduced-motion: reduce) { * { transition: none !important; } }
+</style>
+
+<div class="panel">
+  <header class="head">
+    <span class="mark">Twistify</span>
+    <span class="head-note">Applied to every layer as it is sliced</span>
+  </header>
+
+  <div class="work">
+    <div>
+      <div class="rows" id="rows"></div>
+      <p class="readout" id="readout"></p>
+    </div>
+
+    <figure class="plot">
+      <svg id="plot" viewBox="0 0 180 208" aria-hidden="true"></svg>
+      <figcaption id="plotNote"></figcaption>
+    </figure>
+  </div>
+
+  <footer class="foot">
+    <span class="state" id="state"></span>
+    <button type="button" id="restore">Restore defaults</button>
+    <button type="button" id="save" class="go">Save</button>
+  </footer>
+</div>
+
+<script>
+(function () {
+  var DEFAULTS = __ORCA_DEFAULTS__;
+
+  // Presentation only. `neutral` marks the value at which the control contributes no deformation;
+  // rows without one (period, floor) are shape parameters, not amounts.
+  var FIELDS = [
+    { key: "twist_deg_per_mm", label: "Twist", unit: "\\u00b0/mm", min: -20, max: 20, step: 0.1, dp: 1, neutral: 0,
+      hint: "Rotation added per millimetre of height." },
+    { key: "taper_per_mm", label: "Taper", unit: "/mm", min: -0.05, max: 0.05, step: 0.001, dp: 3, neutral: 0,
+      hint: "Scale added per millimetre. Negative narrows the model as it rises." },
+    { key: "wobble_ampl_mm", label: "Wobble", unit: "mm", min: 0, max: 10, step: 0.1, dp: 1, neutral: 0,
+      hint: "How far each layer slides in X, from centre to peak." },
+    { key: "wobble_period_mm", label: "Wobble period", unit: "mm", min: 1, max: 120, step: 1, dp: 0,
+      hint: "Height of one full wobble cycle." },
+    { key: "min_scale", label: "Scale floor", unit: "\\u00d7", min: 0.01, max: 1, step: 0.01, dp: 2,
+      hint: "Taper never shrinks a layer past this, so a tall model cannot collapse." }
+  ];
+
+  // The preview simulates this much height. Nothing reads the real model, so say so in the caption
+  // rather than implying the drawing is to scale with the plate.
+  var Z_SPAN = 40;
+  var Z_STEP = 2;
+
+  var form = {};
+  var stored = {};
+  var context = (window.orca && window.orca.getContext) ? window.orca.getContext() : { scope: "global" };
+  var savedNoteTimer = 0;
+
+  function num(value, fallback) {
+    var n = parseFloat(value);
+    return isFinite(n) ? n : fallback;
+  }
+
+  function merged(config) {
+    var out = {};
+    Object.keys(DEFAULTS).forEach(function (key) {
+      out[key] = num(config ? config[key] : undefined, DEFAULTS[key]);
+    });
+    return out;
+  }
+
+  function isDirty() {
+    return Object.keys(DEFAULTS).some(function (key) { return form[key] !== stored[key]; });
+  }
+
+  // --- the transform, exactly as _layer_params() applies it -------------------------------------
+
+  function layerAt(z) {
+    var theta = form.twist_deg_per_mm * z * Math.PI / 180;
+    var scale = Math.max(form.min_scale, 1 + form.taper_per_mm * z);
+    var shift = 0;
+    if (form.wobble_ampl_mm !== 0 && form.wobble_period_mm > 0)
+      shift = form.wobble_ampl_mm * Math.sin(2 * Math.PI * z / form.wobble_period_mm);
+    return { theta: theta, scale: scale, shift: shift };
+  }
+
+  function deforms() {
+    return form.twist_deg_per_mm !== 0 || form.taper_per_mm !== 0 || form.wobble_ampl_mm !== 0;
+  }
+
+  // --- drawing ----------------------------------------------------------------------------------
+
+  var ISO_X = 0.866, ISO_Y = 0.5;     // isometric: plan outlines stacked by height
+  var ORIGIN_X = 108, ORIGIN_Y = 182; // the z = 0 outline's centre, in viewBox units
+  var PLAN = 20;                      // half-width of the sample contour
+  var Z_UNITS = 3.3;                  // viewBox units per millimetre of height
+  var MM = 1.5;                       // viewBox units per millimetre of wobble travel
+  var REACH = 62;                     // how far sideways the drawing may run before it is scaled down
+
+  // Plan-view corners of the layer at `z`, before projection.
+  function planOutline(z) {
+    var layer = layerAt(z);
+    var half = PLAN * layer.scale;
+    var cos = Math.cos(layer.theta), sin = Math.sin(layer.theta);
+    return [[-half, -half], [half, -half], [half, half], [-half, half]].map(function (corner) {
+      return [corner[0] * cos - corner[1] * sin + layer.shift * MM,
+              corner[0] * sin + corner[1] * cos];
+    });
+  }
+
+  function points(plan, z, fit) {
+    return plan.map(function (p) {
+      var x = ORIGIN_X + (p[0] - p[1]) * ISO_X * fit;
+      var y = ORIGIN_Y + (p[0] + p[1]) * ISO_Y * fit - z * Z_UNITS;
+      return x.toFixed(1) + "," + y.toFixed(1);
+    }).join(" ");
+  }
+
+  function draw() {
+    var svg = [];
+    var layers = [];
+    var reach = 0;
+    for (var z = 0; z <= Z_SPAN + 0.001; z += Z_STEP) {
+      var plan = planOutline(z);
+      layers.push({ z: z, plan: plan });
+      plan.forEach(function (p) { reach = Math.max(reach, Math.abs(p[0] - p[1]) * ISO_X); });
+    }
+    // A wide taper or a big wobble would run out of the frame; the drawing scales down to fit rather
+    // than clipping. The Z axis keeps its scale, so the ruler stays true.
+    var fit = reach > REACH ? REACH / reach : 1;
+
+    // Z ruler: the drawing is a height plot, so it gets an axis.
+    for (var mark = 0; mark <= Z_SPAN; mark += 10) {
+      var y = ORIGIN_Y - mark * Z_UNITS;
+      svg.push('<line class="tick" x1="24" y1="' + y.toFixed(1) + '" x2="30" y2="' + y.toFixed(1) + '"/>');
+      svg.push('<text x="20" y="' + (y + 3).toFixed(1) + '" text-anchor="end">' + mark + '</text>');
+    }
+    svg.push('<text x="30" y="' + (ORIGIN_Y - Z_SPAN * Z_UNITS - 11).toFixed(1) +
+             '" text-anchor="end">mm</text>');
+
+    // The stack, faint at the bed and reaching full strength at the top: the deformation grows with Z.
+    var trace = [];
+    layers.forEach(function (layer) {
+      var ring = points(layer.plan, layer.z, fit);
+      svg.push('<polygon class="ring" points="' + ring + '" stroke-opacity="' +
+               (0.18 + 0.82 * layer.z / Z_SPAN).toFixed(2) + '"/>');
+      trace.push(ring.split(" ")[1]);
+    });
+
+    // One corner followed all the way up. On a twisted model this is the helix the walls will run in.
+    svg.push('<polyline class="helix" points="' + trace.join(" ") + '"/>');
+
+    // The datum: the first layer is never transformed, so it is drawn as the reference outline.
+    svg.push('<polygon class="datum" points="' + points(layers[0].plan, 0, fit) + '"/>');
+
+    document.getElementById("plot").innerHTML = svg.join("");
+    document.getElementById("plotNote").textContent =
+      deforms() ? "Sample contour, " + Z_SPAN + " mm of Z" : "Sample contour, undeformed";
+  }
+
+  // --- readout ----------------------------------------------------------------------------------
+
+  function describe() {
+    if (!deforms())
+      return "No deformation. Twistify passes every layer through unchanged.";
+
+    var top = layerAt(Z_SPAN);
+    var parts = [];
+    if (form.twist_deg_per_mm !== 0)
+      parts.push("<b>" + (form.twist_deg_per_mm * Z_SPAN).toFixed(0) + "\\u00b0</b> of rotation");
+    if (form.taper_per_mm !== 0)
+      parts.push("<b>" + top.scale.toFixed(2) + "\\u00d7</b> scale" +
+                 (top.scale === form.min_scale ? " (at the floor)" : ""));
+    if (form.wobble_ampl_mm !== 0)
+      parts.push("<b>\\u00b1" + form.wobble_ampl_mm.toFixed(1) + "</b> mm of wobble");
+    return "At " + Z_SPAN + " mm above the first layer: " + parts.join(", ") + ".";
+  }
+
+  function setReadout(html) { document.getElementById("readout").innerHTML = html; }
+
+  // Whatever the pointer or the keyboard is on explains itself; with neither, the line reports what
+  // the current values add up to.
+  function restoreReadout() {
+    var id = document.activeElement ? document.activeElement.id : "";
+    for (var i = 0; i < FIELDS.length; i++)
+      if (id === "n-" + FIELDS[i].key || id === "r-" + FIELDS[i].key)
+        return setReadout(FIELDS[i].hint);
+    setReadout(describe());
+  }
+
+  function refreshState() {
+    var dirty = isDirty();
+    document.getElementById("save").disabled = context.readOnly || !dirty;
+
+    if (savedNoteTimer)
+      return;   // the "Saved" note owns the line until it expires
+    var state = document.getElementById("state");
+    state.textContent = context.readOnly ? "This configuration is read-only."
+                      : dirty ? "Unsaved changes" : "";
+    state.classList.toggle("dirty", dirty && !context.readOnly);
+  }
+
+  function announce(message) {
+    var state = document.getElementById("state");
+    state.textContent = message;
+    state.classList.remove("dirty");
+    clearTimeout(savedNoteTimer);
+    savedNoteTimer = setTimeout(function () { savedNoteTimer = 0; refreshState(); }, 2200);
+  }
+
+  // --- controls ---------------------------------------------------------------------------------
+
+  function detent(field) {
+    if (field.neutral === undefined) return "";
+    return ((field.neutral - field.min) / (field.max - field.min) * 100).toFixed(2) + "%";
+  }
+
+  function clamp(field, value) { return Math.min(field.max, Math.max(field.min, value)); }
+
+  // `echo` rewrites the number field with the clamped, formatted value. Off while the user is still
+  // typing: "-" and "0.0" are valid things to have typed so far, and replacing them mid-keystroke
+  // would fight the person doing it. The drawing still follows every keystroke.
+  function apply(field, value, echo) {
+    form[field.key] = clamp(field, value);
+    if (echo)
+      document.getElementById("n-" + field.key).value = form[field.key].toFixed(field.dp);
+    document.getElementById("r-" + field.key).value = form[field.key];
+    draw();
+    // A control explains itself while you approach it and reports while you change it: once a value
+    // moves, what matters is the total it adds up to, not what the control does.
+    setReadout(describe());
+    refreshState();
+  }
+
+  function buildRows() {
+    var host = document.getElementById("rows");
+    FIELDS.forEach(function (field) {
+      var row = document.createElement("div");
+      row.className = "row";
+      // The number input is the labelled, keyboard-reachable control; the rail is the same value by
+      // pointer, so it stays out of the tab order and out of the accessibility tree.
+      row.innerHTML =
+        '<label class="row-label" for="n-' + field.key + '">' + field.label + '</label>' +
+        '<span class="row-figure">' +
+          '<input id="n-' + field.key + '" type="number" step="' + field.step + '" ' +
+                 'min="' + field.min + '" max="' + field.max + '">' +
+          '<span class="unit">' + field.unit + '</span>' +
+        '</span>' +
+        '<span class="rail"' + (field.neutral === undefined ? "" : ' data-detent style="--detent:' + detent(field) + '"') + '>' +
+          '<input id="r-' + field.key + '" type="range" step="' + field.step + '" ' +
+                 'min="' + field.min + '" max="' + field.max + '" tabindex="-1" aria-hidden="true">' +
+        '</span>';
+      host.appendChild(row);
+
+      var number = row.querySelector("#n-" + field.key);
+      var range = row.querySelector("#r-" + field.key);
+      number.addEventListener("input", function () { apply(field, num(number.value, form[field.key]), false); });
+      number.addEventListener("change", function () { apply(field, num(number.value, DEFAULTS[field.key]), true); });
+      range.addEventListener("input", function () { apply(field, num(range.value, form[field.key]), true); });
+
+      [number, range].forEach(function (input) {
+        input.addEventListener("focus", function () { setReadout(field.hint); });
+        input.addEventListener("mouseenter", function () { setReadout(field.hint); });
+        input.addEventListener("blur", restoreReadout);
+        input.addEventListener("mouseleave", restoreReadout);
+      });
+    });
+  }
+
+  function load(config) {
+    stored = merged(config);
+    form = merged(config);
+    FIELDS.forEach(function (field) {
+      document.getElementById("n-" + field.key).value = form[field.key].toFixed(field.dp);
+      document.getElementById("r-" + field.key).value = form[field.key];
+    });
+    draw();
+    restoreReadout();
+    refreshState();
+  }
+
+  // "Restore defaults" writes the plugin's own defaults globally, but in a preset it discards that
+  // preset's override and falls back to the global configuration. Two different actions, so the
+  // button says which one it is.
+  function labelRestore() {
+    var restore = document.getElementById("restore");
+    var preset = context.scope === "preset";
+    restore.textContent = preset ? "Use global settings" : "Restore defaults";
+    restore.title = preset ? "Discard this preset's override and use the global configuration"
+                           : "Replace the saved configuration with Twistify's defaults";
+    restore.disabled = context.readOnly || (preset && !context.hasPresetOverride);
+  }
+
+  function setInputsEnabled(enabled) {
+    FIELDS.forEach(function (field) {
+      document.getElementById("n-" + field.key).disabled = !enabled;
+      document.getElementById("r-" + field.key).disabled = !enabled;
+    });
+  }
+
+  buildRows();
+  load(window.orca ? window.orca.getConfig() : {});
+  labelRestore();
+  setInputsEnabled(!context.readOnly);
+
+  document.getElementById("save").addEventListener("click", function () {
+    if (!window.orca) return;
+    window.orca.saveConfig(form);
+  });
+  document.getElementById("restore").addEventListener("click", function () {
+    if (window.orca) window.orca.restoreDefaults();
+  });
+
+  if (window.orca && window.orca.onConfig) {
+    var first = true;
+    window.orca.onConfig(function (config) {
+      // Fires once immediately (already handled above) and then whenever the host persists
+      // something: reload from what was stored, never from what was typed.
+      if (first) { first = false; return; }
+      if (window.orca.getContext) context = window.orca.getContext();
+      load(config);
+      labelRestore();
+      setInputsEnabled(!context.readOnly);
+      announce("Saved");
+    });
+  }
+  // Nothing to do for a theme change: every colour on the page, the drawing included, resolves
+  // through the --orca-* variables the host rewrites in place.
+})();
+</script>
+"""
+
+
 class Twistify(orca.slicing.SlicingPipelineCapabilityBase):
     def get_name(self):
         return "Twistify"
-    
+
     def get_default_config(self):
         return _DEFAULTS
 
+    def has_config_ui(self):
+        return True
+
+    def get_config_ui(self):
+        return _CONFIG_UI.replace("__ORCA_DEFAULTS__", json.dumps(_DEFAULTS))
+
     def execute(self, ctx):
         if ctx.step != orca.slicing.Step.posSlice or ctx.object is None:
             return orca.ExecutionResult.success()
diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index 0d31f6c04c..1a4131aca2 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -1254,7 +1254,8 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "interlocking_beam_layer_count"
             || opt_key == "interlocking_depth"
             || opt_key == "interlocking_boundary_avoidance"
-            || opt_key == "interlocking_beam_width") {
+            || opt_key == "interlocking_beam_width"
+            || opt_key == "plugin_config_overrides") {
             steps.emplace_back(posSlice);
 		} else if (
                opt_key == "elefant_foot_compensation"