I also need this functionality. I see how I can send midi with a button press on the external foot switch but I need it per program.

I envision the following:

Choose – Amazing Clean Program – On load send midi to relay to switch to clean channel.

Choose – Amazing Dirt Program – On load send midi to relay to switch to dirt channel.

Still should be able to set an external switch to control the relay whenever but certain Programs will always be clean or dirty.

Right now I need a whole separate midi controller to handle this.