Shift+select is working great now, and the cursor advances correctly on the effects columns and keyjam doesn't make terrible noise but I also can't keyjam any chords on F4 anymore.

and the vu meters work for adlib samples again, and the compatible gxx switch finally actually does what it's supposed to now, and the pitch envelope is looping at the correct position!

Actually it seems like it just isn't taking the instruments into consideration at all. I'll look at it tomorrow, BUT I think I've been more than productive enough for a night :)