Sure, we could do that. I would let a short tap of Super pop up a normal main menu though, like on the Pandora. But a long press could show those things in an overlay, and of course if you want to do the Super+letter shortcuts, you don't have to wait for the overlay to show up. So yes, maybe hardware toggles are not a good default for Usr1 and Usr2, since we can cover that already with Super. Maybe context-menu key (also available as Shift-F10, but maybe a direct key is easier)?