Switching instrument midstaff should switch to correct transposition
It is very good that is possible write different instrument into one stave, when some player is able to change them. Earlier I used to write stave text and switch channel, that I prepared by editing instrument file. But I had one essential problem: I could not provide that instrument may transpose different way than the original instrument (example - player of oboe takes an alto recorder; or player of clarinet takes saxophone). This I expected from instrument switcher.
Maybe you see it not as a bug, but if I will write right notes for player, they will be playbacked incorrectly and if I write them for playback, then the human player will have problems.