Dammit, I wish I had the time to join you all in this one, as this is a topic I have quite a lot of experience in, also programming custom layers on Roli products.
If there is a conversation on this topic happening elsewere in the forum, I would be delighted to be pointed in such direction.
I commented a while back in this post about MPE and roli, and this one about the midi router , but I have yet to think of a proper solution to the problem.
Indeed if vital brings a MPE synth that runs well on zynthian it might be really interesting to get the conversation on this topic a bit more developed into Issues and Feature requests