System Exclusive messages are hugely versatile for synth players wanting to manipulate their sounds in live performance. Admittedly they are a bit ‘complex’ for the average user, but the MIDI Maestro could at least (eventually, when it develops further) allow programmability for Sysex strings through the App, which can be transmitted whenever the assigned pedal is activated. You can leave it to users to know what to write in between the F0 and F7 bytes!
…even better would be to have this functionality but allow one or more ‘highlighted’ bytes within the string to be modulated by a connected expression pedal…
Thanks for considering!