[🐴] Minor nits (#4102)

* set a better size for `initialNumToRender`

* memo list items

* scroll to end on both platforms

* rev

src/screens/Messages/List/index.tsx

@@ -73,7 +73,7 @@ export function MessagesScreen({navigation, route}: Props) {
     )
   }, [_, t])
 
-  const initialNumToRender = useInitialNumToRender()
+  const initialNumToRender = useInitialNumToRender(80)
   const [isPTRing, setIsPTRing] = useState(false)
 
   const {