diff --git a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
index 9f0c780..931579b 100644
--- a/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-metadata/gr-change-metadata_html.ts
@@ -165,7 +165,14 @@
     <section
       class$="[[_computeDisplayState(_showAllSections, change, _SECTION.OWNER)]]"
     >
-      <span class="title">Owner</span>
+      <span class="title">
+        <gr-tooltip-content
+          has-tooltip=""
+          title="This user created or uploaded the first patchset of this change."
+        >
+          Owner
+        </gr-tooltip-content>
+      </span>
       <span class="value">
         <gr-account-chip
           account="[[change.owner]]"
@@ -187,7 +194,14 @@
       </span>
     </section>
     <section class$="[[_computeShowRoleClass(change, _CHANGE_ROLE.UPLOADER)]]">
-      <span class="title">Uploader</span>
+      <span class="title">
+        <gr-tooltip-content
+          has-tooltip=""
+          title="This user uploaded the patchset to Gerrit (typically by running the 'git push' command)."
+        >
+          Uploader
+        </gr-tooltip-content>
+      </span>
       <span class="value">
         <gr-account-chip
           account="[[_getNonOwnerRole(change, _CHANGE_ROLE.UPLOADER)]]"
@@ -197,7 +211,14 @@
       </span>
     </section>
     <section class$="[[_computeShowRoleClass(change, _CHANGE_ROLE.AUTHOR)]]">
-      <span class="title">Author</span>
+      <span class="title">
+        <gr-tooltip-content
+          has-tooltip=""
+          title="This user wrote the code change."
+        >
+          Author
+        </gr-tooltip-content>
+      </span>
       <span class="value">
         <gr-account-chip
           account="[[_getNonOwnerRole(change, _CHANGE_ROLE.AUTHOR)]]"
@@ -206,7 +227,14 @@
       </span>
     </section>
     <section class$="[[_computeShowRoleClass(change, _CHANGE_ROLE.COMMITTER)]]">
-      <span class="title">Committer</span>
+      <span class="title">
+        <gr-tooltip-content
+          has-tooltip=""
+          title="This user committed the code change to the Git repository (typically to the local Git repo before uploading)."
+        >
+          Committer
+        </gr-tooltip-content>
+      </span>
       <span class="value">
         <gr-account-chip
           account="[[_getNonOwnerRole(change, _CHANGE_ROLE.COMMITTER)]]"
diff --git a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_html.ts b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_html.ts
index 89983ad..59338df 100644
--- a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_html.ts
+++ b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list_html.ts
@@ -309,12 +309,12 @@
           as="headerEndpoint"
         >
           <gr-endpoint-decorator name$="[[headerEndpoint]]" role="columnheader">
-            <gr-endpoint-param
-              name="change"
-              value="[[change]]"
-            ></gr-endpoint-param>
+            <gr-endpoint-param name="change" value="[[change]]">
+            </gr-endpoint-param>
             <gr-endpoint-param name="patchRange" value="[[patchRange]]">
             </gr-endpoint-param>
+            <gr-endpoint-param name="files" value="[[_files]]">
+            </gr-endpoint-param>
           </gr-endpoint-decorator>
         </template>
       </template>
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-image-viewer/gr-image-viewer.ts b/polygerrit-ui/app/elements/diff/gr-diff-image-viewer/gr-image-viewer.ts
index a1e89f5..1d6bc95 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-image-viewer/gr-image-viewer.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-image-viewer/gr-image-viewer.ts
@@ -51,6 +51,8 @@
 
 const DEFAULT_AUTOMATIC_BLINK_TIME_MS = 1000;
 
+const AUTOMATIC_BLINK_BUTTON_ACTIVE_AREA_PIXELS = 350;
+
 /**
  * This components allows the user to rapidly switch between two given images
  * rendered in the same location, to make subtle differences more noticeable.
@@ -78,6 +80,8 @@
 
   @internalProperty() protected automaticBlink = false;
 
+  @internalProperty() protected automaticBlinkShown = false;
+
   @internalProperty() protected zoomedImageStyle: StyleInfo = {};
 
   @query('.imageArea') protected imageArea!: HTMLDivElement;
@@ -86,6 +90,8 @@
 
   @query('#source-image') protected sourceImage!: HTMLImageElement;
 
+  @query('#automatic-blink-button') protected automaticBlinkButton?: Element;
+
   private imageSize: Dimensions = {width: 0, height: 0};
 
   @internalProperty()
@@ -188,14 +194,7 @@
     gr-zoomed-image.revision {
       border-color: var(--revision-image-border-color, rgb(170, 242, 170));
     }
-    .automatic-blink-area {
-      position: absolute;
-      width: 30%;
-      height: 100%;
-      right: 0;
-      bottom: 0;
-    }
-    .automatic-blink-button {
+    #automatic-blink-button {
       position: absolute;
       right: var(--spacing-xl);
       bottom: var(--spacing-xl);
@@ -206,8 +205,8 @@
         --primary-button-background-color
       );
     }
-    .automatic-blink-area:hover .automatic-blink-button,
-    .automatic-blink-button:focus-visible {
+    #automatic-blink-button.show,
+    #automatic-blink-button:focus-visible {
       opacity: 1;
     }
     .checkerboard {
@@ -492,15 +491,14 @@
     `;
 
     const automaticBlink = html`
-      <div class="automatic-blink-area">
-        <paper-fab
-          class="automatic-blink-button"
-          title="Automatic blink"
-          icon="gr-icons:${this.automaticBlink ? 'pause' : 'playArrow'}"
-          @click="${this.toggleAutomaticBlink}"
-        >
-        </paper-fab>
-      </div>
+      <paper-fab
+        id="automatic-blink-button"
+        class="${classMap({show: this.automaticBlinkShown})}"
+        title="Automatic blink"
+        icon="gr-icons:${this.automaticBlink ? 'pause' : 'playArrow'}"
+        @click="${this.toggleAutomaticBlink}"
+      >
+      </paper-fab>
     `;
 
     // To pass CSS mixins for @apply to Polymer components, they need to be
@@ -564,7 +562,11 @@
 
     return html`
       ${customStyle}
-      <div class="imageArea" @mousemove="${this.mousemoveMagnifier}">
+      <div
+        class="imageArea"
+        @mousemove="${this.mousemoveImageArea}"
+        @mouseleave="${this.mouseleaveImageArea}"
+      >
         <gr-zoomed-image
           class="${classMap({
             base: this.baseSelected,
@@ -699,6 +701,28 @@
     );
   }
 
+  mousemoveImageArea(event: MouseEvent) {
+    if (this.automaticBlinkButton) {
+      this.updateAutomaticBlinkVisibility(event);
+    }
+    this.mousemoveMagnifier(event);
+  }
+
+  private updateAutomaticBlinkVisibility(event: MouseEvent) {
+    const rect = this.automaticBlinkButton!.getBoundingClientRect();
+    const centerX = rect.left + (rect.right - rect.left) / 2;
+    const centerY = rect.top + (rect.bottom - rect.top) / 2;
+    const distX = Math.abs(centerX - event.clientX);
+    const distY = Math.abs(centerY - event.clientY);
+    this.automaticBlinkShown =
+      distX < AUTOMATIC_BLINK_BUTTON_ACTIVE_AREA_PIXELS &&
+      distY < AUTOMATIC_BLINK_BUTTON_ACTIVE_AREA_PIXELS;
+  }
+
+  mouseleaveImageArea() {
+    this.automaticBlinkShown = false;
+  }
+
   mousedownMagnifier(event: MouseEvent) {
     if (event.buttons === 1) {
       this.ownsMouseDown = true;
diff --git a/polygerrit-ui/app/services/app-context-init.ts b/polygerrit-ui/app/services/app-context-init.ts
index dab894e..9af86d2 100644
--- a/polygerrit-ui/app/services/app-context-init.ts
+++ b/polygerrit-ui/app/services/app-context-init.ts
@@ -73,7 +73,7 @@
     authService: () => new Auth(appContext.eventEmitter),
     restApiService: () => new GrRestApiInterface(appContext.authService),
     changeService: () => new ChangeService(),
-    checksService: () => new ChecksService(),
+    checksService: () => new ChecksService(appContext.reportingService),
     jsApiService: () => new GrJsApiInterface(),
     storageService: () => new GrStorageService(),
     configService: () => new ConfigService(),
diff --git a/polygerrit-ui/app/services/checks/checks-service.ts b/polygerrit-ui/app/services/checks/checks-service.ts
index 250cea5..c517fb89 100644
--- a/polygerrit-ui/app/services/checks/checks-service.ts
+++ b/polygerrit-ui/app/services/checks/checks-service.ts
@@ -54,6 +54,7 @@
 import {getCurrentRevision} from '../../utils/change-util';
 import {getShaByPatchNum} from '../../utils/patch-set-util';
 import {assertIsDefined} from '../../utils/common-util';
+import {ReportingService} from '../gr-reporting/gr-reporting';
 
 export class ChecksService {
   private readonly providers: {[name: string]: ChecksProvider} = {};
@@ -64,7 +65,7 @@
 
   private readonly documentVisibilityChange$ = new BehaviorSubject(undefined);
 
-  constructor() {
+  constructor(readonly reporting: ReportingService) {
     checkToPluginMap$.subscribe(map => {
       this.checkToPluginMap = map;
     });
@@ -150,8 +151,7 @@
               commmitMessage: getCurrentRevision(change)?.commit?.message,
               changeInfo: change,
             };
-            updateStateSetLoading(pluginName);
-            return from(this.providers[pluginName].fetch(data));
+            return this.fetchResults(pluginName, data);
           }
         ),
         catchError(e => {
@@ -183,4 +183,16 @@
         }
       });
   }
+
+  private fetchResults(pluginName: string, data: ChangeData) {
+    updateStateSetLoading(pluginName);
+    const timer = this.reporting.getTimer('ChecksPluginFetch');
+    const fetchPromise = this.providers[pluginName]
+      .fetch(data)
+      .then(response => {
+        timer.end({pluginName});
+        return response;
+      });
+    return from(fetchPromise);
+  }
 }
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
index d7081ce..bbdb02a 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
@@ -24,7 +24,7 @@
 
 export interface Timer {
   reset(): this;
-  end(): this;
+  end(eventDetails?: EventDetails): this;
   withMaximum(maximum: number): this;
 }
 
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
index 5fd4234..4e6ece2 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
@@ -713,7 +713,7 @@
       },
 
       // Stop the timer and report the intervening time.
-      end: () => {
+      end: (eventDetails?: EventDetails) => {
         if (called) {
           throw new Error(`Timer for "${name}" already ended.`);
         }
@@ -725,7 +725,7 @@
           return timer;
         }
 
-        this._reportTiming(name, time);
+        this._reportTiming(name, time, eventDetails);
         return timer;
       },