It's not a big deal for me to carry a laptop. The lid doesn't need to be even open. Midi pedals, and controllers do all the control.
You could do a Mac mini, or small PC in a rack, like Stefan Lessard
One big benefit is presets, as many as you like. Even down to each song have a set you can toggle through. And you can add a VSTi, like a synth, if you have an opportunity for some songs.
PC's are already next to FOH boards, and keyboard players already. Why should they have all the fun?
“Please don’t make the mistake of thinking that the arts and sciences are at odds with one another. That is a recent, stupid and damaging idea..." Tim Minchin