Update to the last post since edits are not possible (unless I’m missing something):
I know that the Listen bus is straight from the PAFL path, so a true solo operation is not possible with this mixer. It would be cool if A&H added an option in Mixer Config / Role page for PAFL/Solo operation of the PAFL buttons. That would make the SQ a much better DAW companion.
The work around for now is to just Solo DAW tracks using the DAW Control layer, but it’s not a 100% solution because it doesn’t work for any other sources. Things like hardware synths or live microphones would not be muted when something gets soloed.