I would love it! In fact, I asked for it at DCS Wish List thread! :smilewink:
For those who say your mouse is over the switch, yes, it's obvious, but next time you want to use it you could remember the shortcut. I remember the Ctrl+Z shortcut because I've seen it many times next to "Undo", that's the way it works. Perhaps next time you want to turn a switch on you cannot move your POV to the cockpit or your right hand to the mouse.
If you add keyboard shortcuts to the tooltips, could you enclose them in brackets?
Battery 2 [LCtrl+LAlt+LShift+W]