It would be nice if the On/Off option, available in the routing section of a chanel, could be controlled via Midi. Then a integration into Companion would be possible.
Right now only the send level can be controlled.
If you do not require a large number of channel to mix on/off options, it is possible to save each option as a scene with only that option change active, the recall the scene by MIDI. Not perfect but should work, the Avantis I use is in our church so can’t try it right now.