Hey Kris, thanks for the suggestion. All this morphing kind of behavior... we don't do it yet. One of our big goals, and it will take months, is to incorporate MJDJ MIDI Morph (our free app) into MIDI Designer.
So the question for right now for you (representing hundreds of users, let's assume) is: does your MIDI route through a computer? Then MD could control MJDJ and we could do the transposition there for ya.