I would like to have the ability to group my solo bus selections together and assign them to a user function button (1-8) similar to the way the mute groups are done. (Section 8.1.1.2 User Buttons Assigns)
This way if I have a preset number of channels I'd like to listen to on my solo bus, I could just simply select the appropriate user button, that I have already configured to do so. Toggling the user button would ideally allow me to un-solo those channels and revert to whatever selections I previously had.
Otherwise, maybe add a feature whereby a group of channels can be solo'd together by way of an Auto Group, similar to the way the auto-group feature works when creating a filter DCA grouping. (i.e., channels within the same category - Drums, Horns, Vocals, etc).
In either case, just something that would speed the workflow of listening to the mix and isolating different channels on the solo bus during a live performance.