I've been looking at getting a programmable pedal switcher and was wondering if any of the ones that also have MIDI support would also be able to change patches on my line6 M9?
Hi Dave.

Well, without knowing the product entirely, I would say you should try reading the manual of the M9, because often these questions are answered in there. IMO, I think that it's possible. If it's possible to 'assign' certain switches/footswitches/MIDI or whatever, then there should be a chance.. :-)
Good luck!