Just a quick thought, but have you tried looking at a single foot switch that has dual contacts ganged together, but one wired normally open, and the other wired normally closed?

Essentially, one of them should not register as a contact until the pedal is released, the other one will register as a contact as the pedal is pressed. Two separate outputs (one from each contact) going to two separate FC7 inputs.

That ought to at least give you a toggle between two adjacent performances.

Or have you actually tried this?