diff --git a/edit.html b/edit.html
index a0fde99d..5d7d0c00 100644
--- a/edit.html
+++ b/edit.html
@@ -23,11 +23,11 @@
     <script src="js/polyfill.js"></script>
     <script src="js/dom.js"></script>
     <script src="js/messaging.js"></script>
+    <script src="js/msg.js"></script>
     <script src="js/prefs.js"></script>
     <script src="js/localization.js"></script>
     <script src="js/script-loader.js"></script>
     <script src="js/storage-util.js"></script>
-    <script src="js/msg.js"></script>
 
     <script src="content/style-injector.js"></script>
     <script src="content/apply.js"></script>
diff --git a/js/msg.js b/js/msg.js
index 26dba45d..53f17bfa 100644
--- a/js/msg.js
+++ b/js/msg.js
@@ -33,7 +33,8 @@ self.msg = self.INJECTED === 1 ? self.msg : (() => {
     onExtension,
     off,
     RX_NO_RECEIVER,
-    RX_PORT_CLOSED
+    RX_PORT_CLOSED,
+    isBg,
   };
 
   function getBg() {
diff --git a/js/prefs.js b/js/prefs.js
index bb3ba650..c7fb981c 100644
--- a/js/prefs.js
+++ b/js/prefs.js
@@ -1,6 +1,8 @@
-/* global promisifyChrome */
+/* global promisifyChrome msg API */
 'use strict';
 
+// Needs msg.js loaded first
+
 self.prefs = self.INJECTED === 1 ? self.prefs : (() => {
   const defaults = {
     'openEditInWindow': false,      // new editor opens in a own browser window
@@ -112,12 +114,11 @@ self.prefs = self.INJECTED === 1 ? self.prefs : (() => {
     'storage.sync': ['get', 'set'],
   });
 
-  const initializing = browser.storage.sync.get('settings')
-    .then(result => {
-      if (result.settings) {
-        setAll(result.settings, true);
-      }
-    });
+  const initializing = (
+    msg.isBg
+      ? browser.storage.sync.get('settings').then(res => res.settings)
+      : API.getPrefs()
+  ).then(res => res && setAll(res, true));
 
   chrome.storage.onChanged.addListener((changes, area) => {
     if (area !== 'sync' || !changes.settings || !changes.settings.newValue) {
diff --git a/js/script-loader.js b/js/script-loader.js
index ada07824..2517951f 100644
--- a/js/script-loader.js
+++ b/js/script-loader.js
@@ -48,73 +48,3 @@ const loadScript = (() => {
     ));
   };
 })();
-
-
-(() => {
-  let subscribers, observer;
-  // natively declared <script> elements in html can't have onload= attribute
-  // due to the default extension CSP that forbids inline code (and we don't want to relax it),
-  // so we're using MutationObserver to add onload event listener to the script element to be loaded
-  window.onDOMscriptReady = (srcSuffix, timeout = 1000) => {
-    if (!subscribers) {
-      subscribers = new Map();
-      observer = new MutationObserver(observe);
-      observer.observe(document.head, {childList: true});
-    }
-    return new Promise((resolve, reject) => {
-      const listeners = subscribers.get(srcSuffix);
-      if (listeners) {
-        listeners.push(resolve);
-      } else {
-        subscribers.set(srcSuffix, [resolve]);
-      }
-      // a resolved Promise won't reject anymore
-      setTimeout(() => {
-        emptyAfterCleanup(srcSuffix);
-        reject(new Error('Timeout'));
-      }, timeout);
-    });
-  };
-
-  return;
-
-  function observe(mutations) {
-    for (const {addedNodes} of mutations) {
-      for (const n of addedNodes) {
-        if (n.src && getSubscribersForSrc(n.src)) {
-          n.addEventListener('load', notifySubscribers, {once: true});
-        }
-      }
-    }
-  }
-
-  function getSubscribersForSrc(src) {
-    for (const [suffix, listeners] of subscribers.entries()) {
-      if (src.endsWith(suffix)) {
-        return {suffix, listeners};
-      }
-    }
-  }
-
-  function notifySubscribers(event) {
-    for (let data; (data = getSubscribersForSrc(this.src));) {
-      data.listeners.forEach(fn => fn(event));
-      if (emptyAfterCleanup(data.suffix)) {
-        return;
-      }
-    }
-  }
-
-  function emptyAfterCleanup(suffix) {
-    if (!subscribers) {
-      return true;
-    }
-    subscribers.delete(suffix);
-    if (!subscribers.size) {
-      observer.disconnect();
-      observer = null;
-      subscribers = null;
-      return true;
-    }
-  }
-})();
diff --git a/manage.html b/manage.html
index 6744d802..28b885f5 100644
--- a/manage.html
+++ b/manage.html
@@ -149,8 +149,8 @@
   <script src="js/polyfill.js"></script>
   <script src="js/dom.js"></script>
   <script src="js/messaging.js"></script>
-  <script src="js/prefs.js"></script>
   <script src="js/msg.js"></script>
+  <script src="js/prefs.js"></script>
   <script src="js/router.js"></script>
   <script src="content/style-injector.js"></script>
   <script src="content/apply.js"></script>
diff --git a/manage/filters.js b/manage/filters.js
index 11e11feb..3d670dfe 100644
--- a/manage/filters.js
+++ b/manage/filters.js
@@ -14,7 +14,7 @@ let initialized = false;
 router.watch({search: ['search']}, ([search]) => {
   $('#search').value = search || '';
   if (!initialized) {
-    init();
+    initFilters();
     initialized = true;
   } else {
     searchStyles();
@@ -36,7 +36,7 @@ HTMLSelectElement.prototype.adjustWidth = function () {
   parent.replaceChild(this, singleSelect);
 };
 
-function init() {
+function initFilters() {
   $('#search').oninput = e => {
     router.updateSearch('search', e.target.value);
   };
diff --git a/manage/import-export.js b/manage/import-export.js
index 7d08fc89..15261baf 100644
--- a/manage/import-export.js
+++ b/manage/import-export.js
@@ -1,15 +1,11 @@
 /* global messageBox styleSectionsEqual API onDOMready
   tryJSONparse scrollElementIntoView $ $$ API $create t animateElement
-  styleJSONseemsValid */
-/* exported bulkChangeQueue bulkChangeTime */
+  styleJSONseemsValid bulkChangeQueue */
 'use strict';
 
 const STYLISH_DUMP_FILE_EXT = '.txt';
 const STYLUS_BACKUP_FILE_EXT = '.json';
 
-let bulkChangeQueue = [];
-let bulkChangeTime = 0;
-
 onDOMready().then(() => {
   $('#file-all-styles').onclick = () => exportToFile();
   $('#unfile-all-styles').onclick = () => importFromFile({fileTypeFilter: STYLUS_BACKUP_FILE_EXT});
@@ -135,7 +131,7 @@ function importFromString(jsonString) {
       }
     });
     bulkChangeQueue.length = 0;
-    bulkChangeTime = performance.now();
+    bulkChangeQueue.time = performance.now();
     return API.importManyStyles(items.map(i => i.item))
       .then(styles => {
         for (let i = 0; i < styles.length; i++) {
diff --git a/manage/manage.js b/manage/manage.js
index 1d1d28a1..888da2e8 100644
--- a/manage/manage.js
+++ b/manage/manage.js
@@ -4,11 +4,10 @@ global messageBox getStyleWithNoCode
   checkUpdate handleUpdateInstalled
   objectDiff
   configDialog
-  sorter msg prefs API onDOMready $ $$ $create template setupLivePrefs
+  sorter msg prefs API $ $$ $create template setupLivePrefs
   t tWordBreak formatDate
   getOwnTab getActiveTab openURL animateElement sessionStorageHash debounce
   scrollElementIntoView CHROME VIVALDI router
-  bulkChangeTime:true bulkChangeQueue
 */
 'use strict';
 
@@ -18,6 +17,8 @@ const ENTRY_ID_PREFIX_RAW = 'style-';
 const ENTRY_ID_PREFIX = '#' + ENTRY_ID_PREFIX_RAW;
 
 const BULK_THROTTLE_MS = 100;
+const bulkChangeQueue = [];
+bulkChangeQueue.time = 0;
 
 // define pref-mapped ids separately
 const newUI = {
@@ -49,46 +50,10 @@ Promise.all([
   API.getAllStyles(true),
   // FIXME: integrate this into filter.js
   router.getSearch('search') && API.searchDB({query: router.getSearch('search')}),
-  Promise.all([
-    onDOMready(),
-    prefs.initializing,
-  ])
-    .then(() => {
-      initGlobalEvents();
-      if (!VIVALDI) {
-        $$('#header select').forEach(el => el.adjustWidth());
-      }
-    }),
-]).then(args => {
-  showStyles(...args);
-});
-
-msg.onExtension(onRuntimeMessage);
-
-function onRuntimeMessage(msg) {
-  switch (msg.method) {
-    case 'styleUpdated':
-    case 'styleAdded':
-    case 'styleDeleted':
-      bulkChangeQueue.push(msg);
-      if (performance.now() - bulkChangeTime < BULK_THROTTLE_MS) {
-        debounce(handleBulkChange, BULK_THROTTLE_MS);
-      } else {
-        handleBulkChange();
-      }
-      break;
-    case 'styleApply':
-    case 'styleReplaceAll':
-      break;
-    default:
-      return;
-  }
-  setTimeout(sorter.updateStripes, 0, {onlyWhenColumnsChanged: true});
-}
-
-
-function initGlobalEvents() {
-  installed = $('#installed');
+  waitForSelector('#installed'), // needed to avoid flicker due to an extra frame and layout shift
+  prefs.initializing
+]).then(([styles, ids, el]) => {
+  installed = el;
   installed.onclick = handleEvent.entryClicked;
   $('#manage-options-button').onclick = () => router.updateHash('#stylus-options');
   $('#sync-styles').onclick = () => router.updateHash('#stylus-options');
@@ -96,31 +61,12 @@ function initGlobalEvents() {
   // show date installed & last update on hover
   installed.addEventListener('mouseover', handleEvent.lazyAddEntryTitle);
   installed.addEventListener('mouseout', handleEvent.lazyAddEntryTitle);
-
   document.addEventListener('visibilitychange', onVisibilityChange);
-
-  $$('[data-toggle-on-click]').forEach(el => {
-    // dataset on SVG doesn't work in Chrome 49-??, works in 57+
-    const target = $(el.getAttribute('data-toggle-on-click'));
-    el.onclick = event => {
-      event.preventDefault();
-      target.classList.toggle('hidden');
-      if (target.classList.contains('hidden')) {
-        el.removeAttribute('open');
-      } else {
-        el.setAttribute('open', '');
-      }
-    };
-  });
-
   // N.B. triggers existing onchange listeners
   setupLivePrefs();
   sorter.init();
-
   prefs.subscribe(newUI.ids.map(newUI.prefKeyForId), () => switchUI());
-
   switchUI({styleOnly: true});
-
   // translate CSS manually
   document.head.appendChild($create('style', `
     .disabled h2::after {
@@ -133,6 +79,39 @@ function initGlobalEvents() {
       content: "${t('filteredStylesAllHidden')}";
     }
   `));
+  if (!VIVALDI) {
+    $$('#header select').forEach(el => el.adjustWidth());
+  }
+  if (CHROME >= 80 && CHROME <= 88) {
+    // Wrong checkboxes are randomly checked after going back in history, https://crbug.com/1138598
+    addEventListener('pagehide', () => {
+      $$('input[type=checkbox]').forEach((el, i) => (el.name = `bug${i}`));
+    });
+  }
+  showStyles(styles, ids);
+});
+
+msg.onExtension(onRuntimeMessage);
+
+function onRuntimeMessage(msg) {
+  switch (msg.method) {
+    case 'styleUpdated':
+    case 'styleAdded':
+    case 'styleDeleted':
+      bulkChangeQueue.push(msg);
+      if (performance.now() - bulkChangeQueue.time < BULK_THROTTLE_MS) {
+        debounce(handleBulkChange, BULK_THROTTLE_MS);
+      } else {
+        handleBulkChange();
+      }
+      break;
+    case 'styleApply':
+    case 'styleReplaceAll':
+      break;
+    default:
+      return;
+  }
+  setTimeout(sorter.updateStripes, 0, {onlyWhenColumnsChanged: true});
 }
 
 function showStyles(styles = [], matchUrlIds) {
@@ -538,7 +517,7 @@ function handleBulkChange() {
     const {id} = msg.style;
     if (msg.method === 'styleDeleted') {
       handleDelete(id);
-      bulkChangeTime = performance.now();
+      bulkChangeQueue.time = performance.now();
     } else {
       handleUpdateForId(id, msg);
     }
@@ -549,7 +528,7 @@ function handleBulkChange() {
 function handleUpdateForId(id, opts) {
   return API.getStyle(id, true).then(style => {
     handleUpdate(style, opts);
-    bulkChangeTime = performance.now();
+    bulkChangeQueue.time = performance.now();
   });
 }
 
@@ -723,6 +702,20 @@ function highlightEditedStyle() {
   }
 }
 
+function waitForSelector(selector) {
+  // TODO: if used in other places, move to dom.js
+  // TODO: if used concurrently, rework to use just one observer internally
+  return new Promise(resolve => {
+    const mo = new MutationObserver(() => {
+      const el = $(selector);
+      if (el) {
+        mo.disconnect();
+        resolve(el);
+      }
+    });
+    mo.observe(document, {childList: true, subtree: true});
+  });
+}
 
 function embedOptions() {
   let options = $('#stylus-embedded-options');
diff --git a/popup.html b/popup.html
index 677edb81..1a39b3a4 100644
--- a/popup.html
+++ b/popup.html
@@ -180,8 +180,8 @@
   <script src="js/dom.js"></script>
   <script src="js/messaging.js"></script>
   <script src="js/localization.js"></script>
-  <script src="js/prefs.js"></script>
   <script src="js/msg.js"></script>
+  <script src="js/prefs.js"></script>
   <script src="content/style-injector.js"></script>
   <script src="content/apply.js"></script>