Cool, glad ou got it sorted!
Yeah, that is confusing but it does make sense - in "note on" mode the incoming notes will just trigger the MB sequencer to run for the duration of each note that it gets sent. Playing the MB at the same time will overide the incoming midi.
hmmm, I think I see what you mean about letting the sequencer be triggered externally, on one midi channel for perhaps, whilst you could play the MB on another over the top of the sequencer - is that right? Im not sure it could be done though the MB being monophonic - maybe I misunderstand?