Macro to select MIDI track output routing

Yes.

I have a question about your second pic above. It shows that you are routing the MIDI to a set of 4 Tracks - lets call that set of Tracks A. Presumably you have several different combinations of Tracks - B, C, D, etc…

Are these different combos the same across various Projects? Or for example might the B set of Tracks be different in Project X and Project Y?

Don’t have any solid suggestions now, but this seems like the kind of thing that should be possible.

Take a look at this post on routing the Chord Track. Not the same as you are looking for, but it is in the neighborhood. I suspect Virtual MIDI Cables will be part of a solution.