I'm 100% down with the idea of CVable performance mixers, actually. Not only does this give you a proper set of amplitude VCAs for the end of your patch's signal chain, you can automate a lot more with many of them...panning, AUX sends, and so forth. Plus, having CUE outputs to headphones is nothing short of a godsend; if your tuning goes spooey mid-set, just route the problem to the cue and fix it while everything else is going on, and the audience is none the wiser.
Case in point: for my B-day, my partner got me the HUGE TD Virgin Years box, with a bunch of unreleased stuff, and much of that is live. During the Royal Albert Hall set, someone's VCOs went bonkers...and while they were able to snap into a mode that allowed that to be corrected and sort of sound like it was part of the set, had they had something that had that CUE function, there would've been no need for that to wind up on the live master.