Welcome to the forums :)
Are you using Mainstage 1 or 2? AFAIK in MS2 you can assign a button to toggle between one of two patches. Then you can easily map a hardware control to this screen control.
In fact you can assign the Button On/Off to the same parameter (patch) in the Screen Control Inspector.
Scrolling doesn't have to be a pain... you can create Next/prev. Set and Patch buttons.