You can use a sustain pedal to control the motor speed of the Rotary Cabinet plugin in MainStage if you'd like.
It just takes a couple steps:
1. Map the the onscreen pedal. Note the “Momentary behavior” checkbox, so it goes “Fast” when the pedal is held down and back to “Slow” when the pedal is released.
2. Make a second “Send to All” mapping for that Patch if you want the sustain pedal to still also function as a Sustain pedal when that Patch is selected.