that is a nice feature indeed. is there any advantage to making keyboards themselves smarter, rather than keeping them dumb and programming the actual computer to deal with key presses and releases they report?
one feature I'd love to have on my old thinkpad pt_BR keyboards is to map the slash key, placed where the (missing) right-ctrl key should be, to behave as a rctrl modifier if held throughout other key presses and releases, but like slash or question mark if pressed and released without intervening events. I've never got 'round to trying to implement that :-( too much to learn, too little time