15 files changed, 31 insertions, 18 deletions
diff --git a/source/features/batch-mark-files-as-viewed.tsx b/source/features/batch-mark-files-as-viewed.tsx
index b5d26fa3..8f518978 100644
--- a/source/features/batch-mark-files-as-viewed.tsx
+++ b/source/features/batch-mark-files-as-viewed.tsx
@@ -8,7 +8,7 @@ import {clickAll} from './toggle-everything-with-alt';
 
 let previousFile: HTMLElement | undefined;
 
-function remember(event: delegate.Event<Event, HTMLFormElement>): void {
+function remember(event: delegate.Event): void {
 	previousFile = event.delegateTarget.closest<HTMLElement>('.js-file')!;
 }
 
diff --git a/source/features/clone-branch.tsx b/source/features/clone-branch.tsx
index 92a7f64f..0ae953f4 100644
--- a/source/features/clone-branch.tsx
+++ b/source/features/clone-branch.tsx
@@ -38,7 +38,7 @@ async function createBranch(newBranchName: string, baseSha: string): Promise<tru
 	return response.ok || response.message;
 }
 
-async function cloneBranch({delegateTarget: cloneButton}: delegate.Event<MouseEvent, HTMLButtonElement>): Promise<void> {
+async function cloneBranch({delegateTarget: cloneButton}: delegate.Event): Promise<void> {
 	const branchName = cloneButton.closest('[branch]')!.getAttribute('branch')!;
 
 	const currentBranch = getBranchBaseSha(branchName);
diff --git a/source/features/close-out-of-view-modals.tsx b/source/features/close-out-of-view-modals.tsx
index 650f542e..88a8044c 100644
--- a/source/features/close-out-of-view-modals.tsx
+++ b/source/features/close-out-of-view-modals.tsx
@@ -25,7 +25,7 @@ const observer = new IntersectionObserver(entries => {
 
 let lastOpen: number;
 let delegation: delegate.Subscription;
-function menuActivatedHandler(event: CustomEvent): void {
+function menuActivatedHandler(event: delegate.Event): void {
 	const details = event.target as HTMLDetailsElement;
 
 	// Safety check #3742
diff --git a/source/features/convert-release-to-draft.tsx b/source/features/convert-release-to-draft.tsx
index f05d62cb..3bbabc24 100644
--- a/source/features/convert-release-to-draft.tsx
+++ b/source/features/convert-release-to-draft.tsx
@@ -7,7 +7,7 @@ import features from '.';
 import * as api from '../github-helpers/api';
 import LoadingIcon from '../github-helpers/icon-loading';
 
-async function convertToDraft({delegateTarget: draftButton}: delegate.Event<MouseEvent, HTMLButtonElement>): Promise<void> {
+async function convertToDraft({delegateTarget: draftButton}: delegate.Event): Promise<void> {
 	try {
 		draftButton.append(<LoadingIcon className="ml-2 v-align-text-bottom" width={16}/>);
 
diff --git a/source/features/copy-file.tsx b/source/features/copy-file.tsx
index c2f4f924..8ee7fd27 100644
--- a/source/features/copy-file.tsx
+++ b/source/features/copy-file.tsx
@@ -7,7 +7,7 @@ import copyToClipboard from 'copy-text-to-clipboard';
 import features from '.';
 import {groupButtons} from '../github-helpers/group-buttons';
 
-function handleClick({delegateTarget: button}: delegate.Event<MouseEvent, HTMLButtonElement>): void {
+function handleClick({delegateTarget: button}: delegate.Event): void {
 	const file = button.closest('.Box, .js-gist-file-update-container')!;
 	const content = select.all('.blob-code-inner', file)
 		.map(({innerText: line}) => line === '\n' ? '' : line) // Must be `.innerText`
diff --git a/source/features/first-published-tag-for-merged-pr.tsx b/source/features/first-published-tag-for-merged-pr.tsx
index d5901789..135bbc1a 100644
--- a/source/features/first-published-tag-for-merged-pr.tsx
+++ b/source/features/first-published-tag-for-merged-pr.tsx
@@ -6,8 +6,8 @@ import * as pageDetect from 'github-url-detection';
 
 import features from '.';
 import fetchDom from '../helpers/fetch-dom';
-import observeElement from '../helpers/simplified-element-observer';
 import {buildRepoURL, getRepo} from '../github-helpers';
+import onConversationHeaderUpdate from '../github-events/on-conversation-header-update';
 
 const getFirstTag = cache.function(async (commit: string): Promise<string | undefined> => {
 	const firstTag = await fetchDom<HTMLAnchorElement>(
@@ -50,7 +50,8 @@ void features.add(__filebasename, {
 	include: [
 		() => pageDetect.isPRConversation() && pageDetect.isMergedPR()
 	],
-	init() {
-		observeElement(select('#partial-discussion-header')!.parentElement!, init);
-	}
+	additionalListeners: [
+		onConversationHeaderUpdate
+	],
+	init
 });
diff --git a/source/features/hide-useless-comments.tsx b/source/features/hide-useless-comments.tsx
index 30a8d847..3cfb89b7 100644
--- a/source/features/hide-useless-comments.tsx
+++ b/source/features/hide-useless-comments.tsx
@@ -8,7 +8,7 @@ import * as pageDetect from 'github-url-detection';
 import features from '.';
 import isUselessComment from '../helpers/is-useless-comment';
 
-async function unhide(event: delegate.Event<MouseEvent, HTMLButtonElement>): Promise<void> {
+async function unhide(event: delegate.Event): Promise<void> {
 	for (const comment of select.all('.rgh-hidden-comment')) {
 		comment.hidden = false;
 	}
diff --git a/source/features/prevent-duplicate-pr-submission.tsx b/source/features/prevent-duplicate-pr-submission.tsx
index 743d8da8..1d14061f 100644
--- a/source/features/prevent-duplicate-pr-submission.tsx
+++ b/source/features/prevent-duplicate-pr-submission.tsx
@@ -5,7 +5,7 @@ import features from '.';
 
 let previousSubmission = 0;
 
-function preventSubmit(event: delegate.Event<MouseEvent, HTMLButtonElement>): void {
+function preventSubmit(event: delegate.Event): void {
 	if (Date.now() - previousSubmission < 1000) {
 		event.preventDefault();
 	}
diff --git a/source/features/prevent-pr-commit-link-loss.tsx b/source/features/prevent-pr-commit-link-loss.tsx
index 80ea157e..88191cd8 100644
--- a/source/features/prevent-pr-commit-link-loss.tsx
+++ b/source/features/prevent-pr-commit-link-loss.tsx
@@ -25,7 +25,7 @@ function getUI(field: HTMLTextAreaElement): HTMLElement {
 	);
 }
 
-const updateUI = debounceFn(({delegateTarget: field}: delegate.Event<InputEvent, HTMLTextAreaElement>): void => {
+const updateUI = debounceFn(({delegateTarget: field}: delegate.Event<Event, HTMLTextAreaElement>): void => {
 	// The replacement logic is not just in the regex, so it alone can't be used to detect the need for the replacement
 	if (field.value === field.value.replace(prCommitUrlRegex, preventPrCommitLinkLoss) && field.value === field.value.replace(prCompareUrlRegex, preventPrCompareLinkLoss)) {
 		getUI(field).remove();
diff --git a/source/features/quick-review-buttons.tsx b/source/features/quick-review-buttons.tsx
index a67dba0e..1985e635 100644
--- a/source/features/quick-review-buttons.tsx
+++ b/source/features/quick-review-buttons.tsx
@@ -73,7 +73,7 @@ function init(): false | void {
 	select('[type="submit"]:not([name])', form)!.remove(); // The selector excludes the "Cancel" button
 
 	// This will prevent submission when clicking "Comment" and "Request changes" without entering a comment and no other review comments are pending
-	delegate<HTMLButtonElement>(form, 'button', 'click', ({delegateTarget: {value}}) => {
+	delegate(form, 'button', 'click', ({delegateTarget: {value}}) => {
 		const pendingComments = looseParseInt(select('.js-reviews-toggle .js-pending-review-comment-count')!);
 		const submissionRequiresComment = pendingComments === 0 && (value === 'reject' || value === 'comment');
 		select('#pull_request_review_body', form)!.toggleAttribute('required', submissionRequiresComment);
diff --git a/source/features/warning-for-disallow-edits.tsx b/source/features/warning-for-disallow-edits.tsx
index 8606cf25..39bdf76f 100644
--- a/source/features/warning-for-disallow-edits.tsx
+++ b/source/features/warning-for-disallow-edits.tsx
@@ -23,7 +23,7 @@ function update(checkbox: HTMLInputElement): void {
 	}
 }
 
-function toggleHandler(event: delegate.Event<UIEvent, HTMLInputElement>): void {
+function toggleHandler(event: delegate.Event<Event, HTMLInputElement>): void {
 	update(event.delegateTarget);
 }
 
@@ -34,7 +34,7 @@ function init(): void | false {
 	}
 
 	update(checkbox); // The sidebar checkbox may already be un-checked
-	delegate(document, '[name="collab_privs"]', 'change', toggleHandler);
+	delegate(document, 'input[name="collab_privs"]', 'change', toggleHandler);
 }
 
 void features.add(__filebasename, {
diff --git a/source/github-events/on-conversation-header-update.ts b/source/github-events/on-conversation-header-update.ts
new file mode 100644
index 00000000..7c85df79
--- /dev/null
+++ b/source/github-events/on-conversation-header-update.ts
@@ -0,0 +1,12 @@
+import select from 'select-dom';
+
+import observeElement from '../helpers/simplified-element-observer';
+
+export default function onConversationHeaderUpdate(callback: VoidFunction): void {
+	const conversationHeader = select('#partial-discussion-header');
+	if (conversationHeader) {
+		observeElement(conversationHeader.parentElement!, callback, {
+			childList: true
+		});
+	}
+}
diff --git a/source/github-events/on-field-keydown.tsx b/source/github-events/on-field-keydown.tsx
index 1b4be8c1..1b7104e3 100644
--- a/source/github-events/on-field-keydown.tsx
+++ b/source/github-events/on-field-keydown.tsx
@@ -4,7 +4,7 @@ import delegate from 'delegate-it';
 type DelegateFieldEvent = delegate.EventHandler<KeyboardEvent, HTMLTextAreaElement>;
 
 function onFieldKeydown(selector: string, callback: DelegateFieldEvent): void {
-	delegate<HTMLTextAreaElement, KeyboardEvent>(document, selector, 'keydown', event => {
+	delegate<HTMLTextAreaElement, 'keydown'>(document, selector, 'keydown', event => {
 		const field = event.delegateTarget;
 
 		// The suggester is GitHub’s autocomplete dropdown
diff --git a/source/globals.d.ts b/source/globals.d.ts
index 7c87ebed..ac8fcde4 100644
--- a/source/globals.d.ts
+++ b/source/globals.d.ts
@@ -32,10 +32,10 @@ interface GlobalEventHandlersEventMap {
 	'page:loaded': CustomEvent;
 	'pjax:start': CustomEvent;
 	'session:resume': CustomEvent;
+	'input': InputEvent; // Remove once no longer necessary (2022?)
 }
 
 declare namespace JSX {
-	interface Element extends SVGElement, HTMLElement, DocumentFragment {}
 	interface IntrinsicElements {
 		'clipboard-copy': IntrinsicElements.button & {for?: string};
 		'details-dialog': IntrinsicElements.div & {tabindex: string};
diff --git a/source/options.tsx b/source/options.tsx
index 6cbeecb9..87d412cb 100644
--- a/source/options.tsx
+++ b/source/options.tsx
@@ -212,7 +212,7 @@ function addEventListeners(): void {
 	select('[name="personalToken"]')!.addEventListener('input', validateToken);
 
 	// Ensure all links open in a new tab #3181
-	delegate(document, '[href^="http"]', 'click', (event: delegate.Event<MouseEvent, HTMLAnchorElement>) => {
+	delegate(document, 'a[href^="http"]', 'click', event => {
 		event.preventDefault();
 		window.open(event.delegateTarget.href);
 	});