Not sure about the GCP, don't have one, but… if you can program it to send a program change message when you hit one of the instant access switches, you could get it to do what you're describing. I know there are some others on this forum that do have a GCP, so I'm sure they'll be able to help you more than I can. The GCP user manual probably has something on this, too.
I do know that you can't do more than one effect at the same time with the MF. But it will definitely switch between any of its 100 presets with MIDI program change messages.
