The multiplexer w/ send & return could work if you don't need the signal to be stereo at the volume control point. It would require more grid space, blocks and CPU% (I think) than what I initially described though.TheloniusJ mentioned that there could be a way to make the multiplexer work with send and return blocks though.
Would the control switches and step sequencer have a lot of cpu overhead?
The extra modifiers (CS on Seq. step parameter, Seq. on 2 bypasses + M-Plex input select) didn't even show an 0.1% CPU increase here on an Axe-FX III Turbo.