diff --git a/platform/mv3/extension/css/picker-ui.css b/platform/mv3/extension/css/picker-ui.css
index 8e86f93d0..8f2fae5ae 100644
--- a/platform/mv3/extension/css/picker-ui.css
+++ b/platform/mv3/extension/css/picker-ui.css
@@ -38,6 +38,7 @@
 #ubol-picker textarea {
     border: 0;
     box-sizing: border-box;
+    font-size: var(--monospace-size);
     min-height: 5em;
     resize: none;
     width: 100%;
@@ -49,7 +50,7 @@
     color: var(--ink-2);
     display: flex;
     flex-direction: column;
-    font-size: small;
+    font-size: var(--monospace-size);
     gap: 0.25em;
 }
 #ubol-picker .resultsetWidgets > span:first-of-type {
@@ -75,7 +76,7 @@
 
 #ubol-picker #candidateFilters {
     font-family: monospace;
-    font-size: small;
+    font-size: var(--monospace-size);
     max-height: min(20em, 30vh);
     min-height: 6em;
     overflow-y: auto;
@@ -111,7 +112,7 @@
     color: var(--ink-2);
     column-gap: 0;
     display: grid;
-    font-size: small;
+    font-size: var(--font-size-smaller);
     grid-template: auto / 1fr 1fr;
     justify-items: stretch;
     user-select: none;
diff --git a/platform/mv3/extension/js/ext.js b/platform/mv3/extension/js/ext.js
index 18c88f878..78fb2c53b 100644
--- a/platform/mv3/extension/js/ext.js
+++ b/platform/mv3/extension/js/ext.js
@@ -33,6 +33,8 @@ export const webextFlavor = (( ) => {
     return extURL.startsWith('moz-extension:') ? 'firefox' : 'chromium';
 })();
 
+const notAnObject = a => typeof a !== 'object' || a === null;
+
 /******************************************************************************/
 
 // The extension's service worker can be evicted at any time, so when we
@@ -47,72 +49,64 @@ export function sendMessage(msg) {
 /******************************************************************************/
 
 export async function localRead(key) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.local instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.local) ) { return; }
     try {
         const bin = await browser.storage.local.get(key);
-        if ( bin instanceof Object === false ) { return; }
+        if ( notAnObject(bin) ) { return; }
         return bin[key] ?? undefined;
     } catch {
     }
 }
 
 export async function localWrite(key, value) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.local instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.local) ) { return; }
     return browser.storage.local.set({ [key]: value });
 }
 
 export async function localRemove(key) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.local instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.local) ) { return; }
     return browser.storage.local.remove(key);
 }
 
 export async function localKeys() {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.local instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.local) ) { return; }
     if ( browser.storage.local.getKeys ) {
         return browser.storage.local.getKeys();
     }
     const bin = await browser.storage.local.get(null);
-    if ( bin instanceof Object === false ) { return; }
+    if ( notAnObject(bin) ) { return; }
     return Object.keys(bin);
 }
 
 /******************************************************************************/
 
 export async function sessionRead(key) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.session instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.session) ) { return; }
     try {
         const bin = await browser.storage.session.get(key);
-        if ( bin instanceof Object === false ) { return; }
+        if ( notAnObject(bin) ) { return; }
         return bin[key] ?? undefined;
     } catch {
     }
 }
 
 export async function sessionWrite(key, value) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.session instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.session) ) { return; }
     return browser.storage.session.set({ [key]: value });
 }
 
 export async function sessionRemove(key) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.session instanceof Object === false ) { return; }
+    if ( notAnObject(browser?.storage?.session) ) { return; }
     return browser.storage.session.remove(key);
 }
 
 /******************************************************************************/
 
 export async function adminRead(key) {
-    if ( browser.storage instanceof Object === false ) { return; }
-    if ( browser.storage.managed instanceof Object === false ) { return; }
+    if ( browser?.storage?.managed instanceof Object === false ) { return; }
     try {
         const bin = await browser.storage.managed.get(key);
-        if ( bin instanceof Object === false ) { return; }
+        if ( notAnObject(bin) ) { return; }
         return bin[key] ?? undefined;
     } catch {
     }