It would be nice if you could use polyphonic staffs while working in the score editor with expression maps. Currently, expressions only apply to the midi track on channel 1 if the track’s midi channel is set to “Any”. The current work around is to duplicate the track and swap around which voice is on channel 1. You would think that the expressions would apply to all voices on the staff, but this is not so.
I also noticed that expressions are tied to a specific note. So if you have a chord and add an expression to it, deleting a note from the chord may delete the expression too(Depending on which note you delete in the chord). This is rather troublesome as it requires you to sometimes add the expressions again when you modify a chord.