So it really works as I thought ! Thanks for testing that !
I was thinking external power switch, but the problem is where to put it. There is not much room inside the OneStar. It would be easy to replace the original momentary action type switch with latching action type, but then, where to put the level switch...
Maybe somekind of 3 position toggle switch, with on-off and momentary on (in the same switch). (Momentary position changes the level) Only problem is that then you have to "mess around with such a nice design" like you guys said.
If you wanna save the rubber cover neat, perhaps its possible to put a miniature push button switch inside case, and use extra 9 volt battery clip like KenBar said. (again, not mutch room for it)