I recently had an idea for a product very similar to this. I was right to assume someone else must have already thought of it too.
The Rigmaster is a system that allows you to control any analog dial with a foot pedal or a tablet. So any knob on any amp or pedal could be controlled. It seems like most equipment will eventually have this capability through usb or midi connections. But until they do, this looks like a well thought out solution, though a bit expensive.
The KickStarter page is HERE.
