I’m currently looking in to this for running a second unit on channel 2.
Still kinda in the weeds… but…
If you plug a usb keyboard (edit: and mouse!) into the rpi and his esc you will back out to desktop view and can open the console along with some helpful readme files…
^basics of ‘ofxmidi’ will be helpful in understanding what you need to adjust in the code lines.
I’ll pm you once I’ve figured out some specifics beyond that… but please feel free to dive in too.