these are interesting hacks, glad you let people know about this possibility.
Another example I can think about: remap the Ro key to toggle between international layout while it's pressed, so you can switch between layouts with a key right next to the shift key.
For example, on a US/RU settting, press Ro while pressing the 6 keys to the right of Tab in a sequence and you would get ЙЦУКЕН, don't press Ro and do the same: you would get QWERTY. Mixing and matching in both upper and lowercase would be very easy.
This still leaves you with the Yen and the Ro key to map for other things!