They can just do what they did in Windows 95 (possibly not in the very first version) where the start button doesn't actually extend all the way into the corner

They can just do what they did in Windows 95 (possibly not in the very first version) where the start button doesn't actually extend all the way into the corner, but clicking the corner pixel teleports the cursor a few pixels inwards, so that the click hits the button. The same fix would work in Windows 11, although it would involve teleporting the cursor halfway across the screen.