Come to think of it though, there would be very few instances where you would want to have the full range of a hot knob parameter mapped to an external expression pedal. Even with ‘mix’ levels for instance, you wouldn’t necessarily want a pedal to sweep through the entire range of a mix knob if you’re just fine tuning say the mix level of a reverb to suit the acoustics of a particular room at a gig. That could be very cumbersome. In which case your back to making all expression parameters programme/preset specific.