Hi @keith
I did some work about that working with Open Stage Control and TouchOSC; this is very old (and for sure bad) code as these were my first attempts in this direction and also you are a professional coder and my stuff is definitely on beginner level.
Nevertheless I just want to let you know that I am interested in SP applications going in this direction; one reason is: I really do like coding and am very curiously to learn more and the best way to get better is just to try - irrespective of the level you start from. The other is, that I planned to integrate this into my live coding practice.
I did also continue with these ideas using a hardware controller but currently I am a bit hesitant as to how much energy for me is worthwhile to invest.