diff --git a/src/edit/codemirror-factory.js b/src/edit/codemirror-factory.js
index 7dacde8234..08e2097af2 100644
--- a/src/edit/codemirror-factory.js
+++ b/src/edit/codemirror-factory.js
@@ -17,7 +17,11 @@ const cms = new Set();
 const cmDefaults = CodeMirror.defaults;
 const cmFactory = {
 
-  /** @return {CodeMirror.Editor} */
+  /**
+   * @param {HTMLElement | ((host: HTMLElement) => void)} place
+   * @param {CodeMirror.EditorConfiguration} [options]
+   * @return {CodeMirror.Editor}
+   */
   create(place, options) {
     const cm = CodeMirror(place, options);
     cm.display.lineDiv.on('mousewheel', plusMinusOnWheel.bind(cm), true);
diff --git a/src/edit/compact-header.js b/src/edit/compact-header.js
index 1d5c234dbc..d0ca49371d 100644
--- a/src/edit/compact-header.js
+++ b/src/edit/compact-header.js
@@ -1,8 +1,13 @@
 import {$create, mqCompact} from '@/js/dom';
 import {important} from '@/js/dom-util';
+import {template} from '@/js/localization';
 import * as prefs from '@/js/prefs';
 import editor from './editor';
 
+const h = template.body.$('#header');
+export const toggleSticky = val => h.classList.toggle('sticky', val);
+export let sticky;
+
 export default function CompactHeader() {
   // Set up mini-header on scroll
   const {isUsercss} = editor;
@@ -40,9 +45,8 @@ export default function CompactHeader() {
 
   /** @param {IntersectionObserverEntry[]} entries */
   function onScrolled(entries) {
-    const h = $id('header');
-    const sticky = !entries.pop().intersectionRatio;
+    sticky = !entries.pop().intersectionRatio;
     if (!isUsercss) scroller.style.paddingTop = sticky ? h.offsetHeight + 'px' : '';
-    h.classList.toggle('sticky', sticky);
+    toggleSticky(sticky);
   }
 }
diff --git a/src/edit/editor.js b/src/edit/editor.js
index bcfe2e3e1c..ea328338e8 100644
--- a/src/edit/editor.js
+++ b/src/edit/editor.js
@@ -1,6 +1,7 @@
 import {$create} from '@/js/dom';
 import * as prefs from '@/js/prefs';
 import {clipString, debounce, deepEqual, mapObj, sessionStore, t} from '@/js/util';
+import {sticky} from './compact-header';
 import DirtyReporter from './dirty-reporter';
 
 const dirty = DirtyReporter();
@@ -28,6 +29,7 @@ const editor = self.editor = {
   },
   regexps,
   saving: false,
+  /** @type {EditorScrollInfoContainer} */
   scrollInfo: {},
   get style() {
     return style;
@@ -44,14 +46,17 @@ const editor = self.editor = {
       cm.setSelections(...si.sel, {scroll: false});
       Object.assign(cm.display.scroller, si.scroll); // for source editor
       Object.assign(cm.doc, si.scroll); // for sectioned editor
+      return si;
     }
   },
 
   cancel: () => location.assign('/manage.html'),
 
   makeScrollInfo() {
-    return {
+    return /** @namespace EditorScrollInfoContainer */ {
+      sticky,
       scrollY: window.scrollY,
+      /** @type {EditorScrollInfo[]} */
       cms: editor.getEditors().map(cm => /** @namespace EditorScrollInfo */({
         bookmarks: (cm.state.sublimeBookmarks || []).map(b => b.find()),
         focus: cm.hasFocus(),
@@ -59,6 +64,7 @@ const editor = self.editor = {
         parentHeight: cm.display.wrapper.parentElement.offsetHeight,
         scroll: mapObj(cm.doc, null, ['scrollLeft', 'scrollTop']),
         sel: [cm.doc.sel.ranges, cm.doc.sel.primIndex],
+        viewTo: cm.display.viewTo,
       })),
     };
   },
diff --git a/src/edit/index.js b/src/edit/index.js
index 45834cc2f6..f6b15423ff 100644
--- a/src/edit/index.js
+++ b/src/edit/index.js
@@ -2,7 +2,7 @@ import '@/js/dom-init';
 import {tBody} from '@/js/localization';
 import * as prefs from '@/js/prefs';
 import {CodeMirror} from '@/cm';
-import CompactHeader from './compact-header';
+import CompactHeader, {toggleSticky} from './compact-header';
 import editor from './editor';
 import EditorHeader from './editor-header';
 import * as linterMan from './linter';
@@ -23,6 +23,7 @@ tBody();
 
 (async () => {
   if (loading) await loading;
+  if (editor.scrollInfo.sticky) toggleSticky(true);
   EditorHeader();
   USWIntegration();
   // TODO: load respective js on demand?
diff --git a/src/edit/moz-section-finder.js b/src/edit/moz-section-finder.js
index da33b05753..92f58703ae 100644
--- a/src/edit/moz-section-finder.js
+++ b/src/edit/moz-section-finder.js
@@ -23,6 +23,7 @@ export default function MozSectionFinder(cm) {
   let updTo;
   let scheduled;
 
+  /** @namespace MozSectionFinder */
   const finder = {
     IGNORE_ORIGIN: KEY,
     EQ_SKIP_KEYS: [
diff --git a/src/edit/moz-section-widget.js b/src/edit/moz-section-widget.js
index 29c0ba6cba..2e319c3025 100644
--- a/src/edit/moz-section-widget.js
+++ b/src/edit/moz-section-widget.js
@@ -229,11 +229,12 @@ export default function MozSectionWidget(cm, finder = MozSectionFinder(cm)) {
     const isDelayed = added.isDelayed && (cm.startOperation(), true);
     const toDelay = [];
     const t0 = performance.now();
-    let {viewFrom, viewTo} = cm.display;
+    let viewTo = editor.viewTo || cm.display.viewTo;
     for (const sec of added) {
       const i = removed.findIndex(isReusableWidget, sec);
       const old = removed[i];
-      if (isDelayed || old || sec.end.line >= viewFrom && sec.start.line < viewTo) {
+      if (isDelayed || old
+      || sec.start.line < viewTo /* must add preceding ones to calc scrollTop*/) {
         renderWidget(sec, old);
         viewTo -= (sec.funcs.length || 1) * 1.25;
         if (old) removed[i] = null;
diff --git a/src/edit/sections-editor-section.js b/src/edit/sections-editor-section.js
index daaa9aaa15..87138252fe 100644
--- a/src/edit/sections-editor-section.js
+++ b/src/edit/sections-editor-section.js
@@ -37,6 +37,9 @@ export default class EditorSection {
       at[prefs.get('editor.targetsFirst') ? 'after' : 'before'](wrapper);
     }, {
       value: sectionData.code,
+      finishInit(_) {
+        editor.applyScrollInfo(_, si);
+      },
     });
     this.elLabelText = elLabel.lastChild;
     cm.el = el;
@@ -66,7 +69,6 @@ export default class EditorSection {
       if (cssName && arr) for (const v of arr) this.addTarget(cssName, v);
     }
     if (!this.targets.length) this.addTarget();
-    editor.applyScrollInfo(cm, si);
     initBeautifyButton(el.$('.beautify-section'), [cm]);
     prefs.subscribe('editor.toc.expanded', this.updateTocPrefToggled.bind(this), true);
     new ResizeGrip(cm); // eslint-disable-line no-use-before-define
diff --git a/src/edit/source-editor.js b/src/edit/source-editor.js
index 169bb901a1..439a6661bd 100644
--- a/src/edit/source-editor.js
+++ b/src/edit/source-editor.js
@@ -27,6 +27,9 @@ export default function SourceEditor() {
   `.replace(/^\s+/gm, '');
   let savedGeneration;
   let prevMode = NaN;
+  /** @type {MozSectionFinder} */
+  let sectionFinder;
+  let sectionWidget;
 
   $$remove('.sectioned-only');
   $id('header').on('wheel', headerOnScroll);
@@ -34,10 +37,23 @@ export default function SourceEditor() {
   $id('sections').appendChild($create('.single-editor'));
   $id('save-button').on('split-btn', saveTemplate);
 
-  const cm = cmFactory.create($('.single-editor'));
+  const cm = cmFactory.create($('.single-editor'), {
+    value: style.id ? style.sourceCode : setupNewStyle(editor.template),
+    finishInit(me) {
+      const si = editor.applyScrollInfo(me) || {};
+      editor.viewTo = si.viewTo;
+      sectionFinder = MozSectionFinder(me);
+      sectionWidget = MozSectionWidget(me, sectionFinder);
+      prefs.subscribe('editor.linter', updateLinterSwitch, true);
+      prefs.subscribe('editor.appliesToLineWidget',
+        (k, val) => sectionWidget.toggle(val), true);
+      prefs.subscribe('editor.toc.expanded',
+        (k, val) => sectionFinder.onOff(editor.updateToc, val), true);
+      Object.assign(me.curOp, si.scroll);
+      editor.viewTo = 0;
+    },
+  });
   const cmpPos = CodeMirror.cmpPos;
-  const sectionFinder = MozSectionFinder(cm);
-  const sectionWidget = MozSectionWidget(cm, sectionFinder);
   const metaCompiler = createMetaCompiler(meta => {
     const {vars} = style[UCD] || {};
     if (vars) {
@@ -53,7 +69,6 @@ export default function SourceEditor() {
     style.url = meta.homepageURL || style.installationUrl;
     updateMeta();
   });
-  if (!style.id) setupNewStyle(editor.template);
   updateMeta();
 
   /** @namespace Editor */
@@ -110,17 +125,6 @@ export default function SourceEditor() {
     scrollToEditor: () => {},
   });
 
-  prefs.subscribe('editor.linter', updateLinterSwitch, true);
-  prefs.subscribe('editor.appliesToLineWidget',
-    (k, val) => sectionWidget.toggle(val), true);
-  prefs.subscribe('editor.toc.expanded',
-    (k, val) => sectionFinder.onOff(editor.updateToc, val), true);
-
-  if (style.id) {
-    cm.setValue(style.sourceCode);
-    cm.clearHistory();
-    cm.markClean();
-  }
   savedGeneration = cm.changeGeneration();
   cm.on('changes', (_, changes) => {
     dirty.modify('sourceGeneration', savedGeneration, cm.changeGeneration());
@@ -139,7 +143,6 @@ export default function SourceEditor() {
   if (!$isTextInput(document.activeElement)) {
     cm.focus();
   }
-  editor.applyScrollInfo(cm); // WARNING! Place it after all cm.XXX calls that change scroll pos
 
   /** Shows the console.log output from the background worker stored in `log` property */
   function showLog(log) {
@@ -183,19 +186,14 @@ export default function SourceEditor() {
     if (Object.keys(sec0).length === 1) { // the only key is 'code'
       sec0.domains = ['example.com'];
     }
-    style.sourceCode = (tpl || DEFAULT_TEMPLATE)
+    return (style.sourceCode = (tpl || DEFAULT_TEMPLATE)
       .replace(/(@name)(?:([\t\x20]+).*|\n)/, (_, k, space) => `${k}${space || ' '}${style.name}`)
       .replace(/\s*@-moz-document[^{]*{([^}]*)}\s*$/g, // stripping dummy sections
         (s, body) => body.trim() === comment ? '\n\n' : s)
       .trim() +
       '\n\n' +
-      styleToCss(style);
-    cm.startOperation();
-    cm.setValue(style.sourceCode);
-    cm.clearHistory();
-    cm.markClean();
-    cm.endOperation();
-    dirty.clear('sourceGeneration');
+      styleToCss(style)
+    );
   }
 
   function updateMeta() {
diff --git a/src/js/color/color-view.js b/src/js/color/color-view.js
index e649124aa4..5e4955ef6e 100644
--- a/src/js/color/color-view.js
+++ b/src/js/color/color-view.js
@@ -11,7 +11,7 @@ export const COLORVIEW_SWATCH_PROP = `--${COLORVIEW_SWATCH_CLASS}`;
 const CLOSE_POPUP_EVENT = 'close-colorpicker-popup';
 
 const {RX_COLOR, testAt} = colorConverter;
-const RX_UNSUPPORTED = (s => s && new RegExp(s))([
+const RX_UNSUPPORTED = !__.MV3 && (s => s && new RegExp(s))([
   !CSS.supports('color', '#abcd') && /#(.{4}){1,2}$/,
   !CSS.supports('color', 'hwb(1 0% 0%)') && /^hwb\(/,
   !CSS.supports('color', 'rgb(1e2,0,0)') && /\de/,