Mapping Combi mixer "Solo" buttons be to MIDI cont

[romandesign]

Mapping Combi mixer "Solo" buttons be to MIDI controller - is this possible?

I just found out that setting "Mute mode" to "Live" on Global page lets you basically switch between sounds seamlessly in live performance using the "Solo" button. There is no sound cut-off like in default "Studio" mode. I can set my song up and stick to a single Combi, making Set List work as intended and still allowing me to switch between a few sounds during a single song, if "Solo" buttons for specific Combi tracks could be mapped to hardware buttons.

Howewer I can't map it to anything but SW1 and SW2. I can spare SW2 but SW1 is needed for many sounds. It would be nice if I could use external controllers to "group-solo" some tracks, but I can't find if it's possible. Are those solo buttons mapped to any MIDI controllers or events?