Something that would be useful to me is the ability to trigger multiple MIDI commands from one Live Mode Button. I can find usefulness in having both the option for it trigger two or more MIDI commands simultaneously OR in succession from within the Button Trigger dialog. (I use Show Express to trigger projection screen images via MIDI - being able to send two messages from one button push would make my programming so much more efficient.)
I would also love to see the ability to implement MIDI from within the Step Editor... but I'll setup a new thread over there.