So, I was planning a purchase of a Mooer Pro Live to pair with my MS-3, against a Neuron (no xlr) or Iridium (no app, no xlr, $$$). It has midi, but only accepts PC commands for changing patches, whereas the other 2 both support CC# for changing parameters within a patch. The Mooer won out, basically because it has a balanced XLR output and can replace Endgame on my board.
But the PC only thing was bugging me. The MS-3 has assigns within a patch, but they can only send CC# - the MS-3 has to change a patch to send a PC message. This didn't seem to be making the most of what the MS-3 can do. So, I figured I could live with changing a patch on the MPL for higher or lower gain if I could convert the CC to PC. Turns out there are devices that will do this, but you can also do it with Arduino... and found a thread here at DIYstompboxes:
https://www.diystompboxes.com/smfforum/index.php?topic=121902.0
I uploaded the program to a cheap chinese nano, converted the layout to vero, and drilled out a cheap plastic box. Turns out I swapped pins 4 and 5 on both the midi in and out jacks, but once that was sorted it worked perfectly. Gutshot and current board.