Great project and great idea, thank you for sharing !

I don't know if it's useful but one technique I have used in sonification during the experimentation phase is to skip the real time aspect, capture all the available "channels" and generate all the possible permutations of what is mapped where.

Then you can listen to the outputs, see what sounds good, and then test it in real time to check if the musicality is actually a result of the physical interaction and not an artifact or a product of noise.