diff --git a/javatests/com/google/gerrit/acceptance/git/AbstractForcePush.java b/javatests/com/google/gerrit/acceptance/git/AbstractForcePush.java
index 88d0937..943d990 100644
--- a/javatests/com/google/gerrit/acceptance/git/AbstractForcePush.java
+++ b/javatests/com/google/gerrit/acceptance/git/AbstractForcePush.java
@@ -21,6 +21,7 @@
 import static org.eclipse.jgit.transport.RemoteRefUpdate.Status.OK;
 import static org.eclipse.jgit.transport.RemoteRefUpdate.Status.REJECTED_OTHER_REASON;
 
+import com.google.common.collect.Iterables;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.testsuite.project.ProjectOperations;
@@ -116,6 +117,28 @@
     assertDeleteRef(OK);
   }
 
+  @Test
+  public void directPushSendsEmail() throws Exception {
+    // create a change
+    PushOneCommit push1 =
+        pushFactory.create(admin.newIdent(), testRepo, "change1", "a.txt", "content");
+    PushOneCommit.Result r = push1.to("refs/for/master");
+    r.assertOkStatus();
+
+    // Add reviewer to receive notifications
+    gApi.changes().id(r.getChangeId()).addReviewer(user.email());
+    sender.clear();
+
+    // direct submit the change
+    PushOneCommit.Result r1 = push1.to("refs/heads/master");
+    r1.assertOkStatus();
+
+    // email received
+    assertThat(sender.getMessages()).hasSize(1);
+    assertThat(Iterables.getOnlyElement(sender.getMessages()).body())
+        .contains("has submitted this change");
+  }
+
   private void assertDeleteRef(RemoteRefUpdate.Status expectedStatus) throws Exception {
     BranchInput in = new BranchInput();
     in.ref = "refs/heads/test";
diff --git a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
index 1908df0..6dd67e4 100644
--- a/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
+++ b/polygerrit-ui/app/elements/diff/gr-apply-fix-dialog/gr-apply-fix-dialog.ts
@@ -41,6 +41,7 @@
 import {ParsedChangeInfo} from '../../../types/types';
 import {GrButton} from '../../shared/gr-button/gr-button';
 import {TokenHighlightLayer} from '../gr-diff-builder/token-highlight-layer';
+import {KnownExperimentId} from '../../../services/flags/flags';
 
 export interface GrApplyFixDialog {
   $: {
@@ -98,7 +99,11 @@
   })
   _disableApplyFixButton = false;
 
-  layers = [new TokenHighlightLayer(this)];
+  layers = appContext.flagsService.isEnabled(
+    KnownExperimentId.TOKEN_HIGHLIGHTING
+  )
+    ? [new TokenHighlightLayer(this)]
+    : [];
 
   private refitOverlay?: () => void;
 
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
index fa3ddf4..c4fed53 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host.ts
@@ -412,7 +412,11 @@
 
   private _getLayers(path: string): DiffLayer[] {
     const layers = [];
-    layers.push(new TokenHighlightLayer(this));
+    if (
+      appContext.flagsService.isEnabled(KnownExperimentId.TOKEN_HIGHLIGHTING)
+    ) {
+      layers.push(new TokenHighlightLayer(this));
+    }
     layers.push(this.syntaxLayer);
     // Get layers from plugins (if any).
     layers.push(...this.jsAPI.getDiffLayers(path));
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.js b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.js
index b24b3ba..344f9d8 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-host/gr-diff-host_test.js
@@ -1270,7 +1270,7 @@
     test('gr-diff-host provides syntax highlighting layer', async () => {
       stubRestApi('getDiff').returns(Promise.resolve({content: []}));
       await element.reload();
-      assert.equal(element.$.diff.layers[1], element.syntaxLayer);
+      assert.equal(element.$.diff.layers[0], element.syntaxLayer);
     });
 
     test('rendering normal-sized diff does not disable syntax', () => {
@@ -1324,7 +1324,7 @@
     test('gr-diff-host provides syntax highlighting layer', async () => {
       stubRestApi('getDiff').returns(Promise.resolve({content: []}));
       await element.reload();
-      assert.equal(element.$.diff.layers[1], element.syntaxLayer);
+      assert.equal(element.$.diff.layers[0], element.syntaxLayer);
     });
 
     test('syntax layer should be disabled', () => {
diff --git a/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread.ts b/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread.ts
index 39a87a2..d6aae5c 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment-thread/gr-comment-thread.ts
@@ -54,6 +54,7 @@
 import {CustomKeyboardEvent} from '../../../types/events';
 import {LineNumber, FILE} from '../../diff/gr-diff/gr-diff-line';
 import {GrButton} from '../gr-button/gr-button';
+import {KnownExperimentId} from '../../../services/flags/flags';
 import {DiffInfo, DiffPreferencesInfo} from '../../../types/diff';
 import {RenderPreferences} from '../../../api/diff';
 import {
@@ -211,6 +212,8 @@
 
   private readonly reporting = appContext.reportingService;
 
+  private readonly flagsService = appContext.flagsService;
+
   private readonly commentsService = appContext.commentsService;
 
   readonly storage = appContext.storageService;
@@ -357,7 +360,9 @@
   _getLayers(diff?: DiffInfo) {
     if (!diff) return [];
     const layers = [];
-    layers.push(new TokenHighlightLayer(this));
+    if (this.flagsService.isEnabled(KnownExperimentId.TOKEN_HIGHLIGHTING)) {
+      layers.push(new TokenHighlightLayer(this));
+    }
     layers.push(this.syntaxLayer);
     return layers;
   }
diff --git a/polygerrit-ui/app/services/flags/flags.ts b/polygerrit-ui/app/services/flags/flags.ts
index 21f3aa4..ef5fde2 100644
--- a/polygerrit-ui/app/services/flags/flags.ts
+++ b/polygerrit-ui/app/services/flags/flags.ts
@@ -25,6 +25,7 @@
  */
 export enum KnownExperimentId {
   NEW_IMAGE_DIFF_UI = 'UiFeature__new_image_diff_ui',
+  TOKEN_HIGHLIGHTING = 'UiFeature__token_highlighting',
   CHECKS_DEVELOPER = 'UiFeature__checks_developer',
   NEW_REPLY_DIALOG = 'UiFeature__new_reply_dialog',
   SUBMIT_REQUIREMENTS_UI = 'UiFeature__submit_requirements_ui',
diff --git a/resources/com/google/gerrit/server/mail/Merged.soy b/resources/com/google/gerrit/server/mail/Merged.soy
index e268a31..b8a19fc 100644
--- a/resources/com/google/gerrit/server/mail/Merged.soy
+++ b/resources/com/google/gerrit/server/mail/Merged.soy
@@ -30,7 +30,7 @@
   {if $email.changeUrl} ( {$email.changeUrl} ){/if}{\n}
   {\n}
 
-  {$email.stickyApprovalDiff}
+  {if $email.stickyApprovalDiff} ( {$email.stickyApprovalDiff} ){/if}
 
   Change subject: {$change.subject}{\n}
   ......................................................................{\n}
diff --git a/resources/com/google/gerrit/server/mail/MergedHtml.soy b/resources/com/google/gerrit/server/mail/MergedHtml.soy
index d2f7bfd..ac4afb3 100644
--- a/resources/com/google/gerrit/server/mail/MergedHtml.soy
+++ b/resources/com/google/gerrit/server/mail/MergedHtml.soy
@@ -32,9 +32,11 @@
     </p>
   {/if}
 
-  {call mailTemplate.UnifiedDiff}
-    {param diffLines: $email.stickyApprovalDiffHtml /}
-  {/call}
+  {if $email.stickyApprovalDiffHtml}
+    {call mailTemplate.UnifiedDiff}
+      {param diffLines: $email.stickyApprovalDiffHtml /}
+    {/call}
+  {/if}
 
   <div style="white-space:pre-wrap">{$email.approvals}</div>