I'd like to know too.
Have any of the hardware mod folks tried taking the regular
M@g tailcap and using the space where the spare incandescent is stored to put in a switch? There are a lot of very tiny switches made for computer hardware, and ... well, it's beyond me but I sure wish it's happen..
A little DIP switch, thumbnail-sized, poked either out the side, out the cutout for the split ring or out the base of the tailcap might work, with an appropriate rubber seal around it.
All it'd have to do is connect the spring with the flashlight case.
Or, heck, everything's getting smart nowadays, how about a switch that detects that it's being held and stays on -- or a magnetic reed that would respond to a little ring rotated around the circumference putting a tiny magnet close to or farther away from it -- or ....
I mean, there's this BIG HOLE in the tailcap of the
M@g, and it's got nothing at all in it now but that little tiny museum piece incandescent bulb ...