Never mind......I was correct the first time. I thought MAYBE you could go into the MIDI menu and assign a MIDI cc# to say External 12 of an effect you never used(like Filter 2 or something). I thought maybe you could throw that block into your preset and not connect it to anything in the signal chain. Then assign External 12 to that Saturation function. Then in the foot switch menu for the preset, just assign whatever pedal you chose to assign it's cc# to External 12 to foot switch 5. Then when you engaged it, it would turn on the Saturation switch, but.....I tried it and had no luck with it.