I realise there’s additional costs involved, but would a ME-1 setup (or partial setup) provide what you’re after? A single ME-1 could grant you an “eighth aux” mix. From there you could add as many or as few additional as you like.
If you have a Qu-24, you could alternatively consider a compromise where one band member is fed from a group, which would provide a subset of the main LR mix based upon assignments.
Not trying to detract from this suggestion, just trying to propose workarounds for the time being 🙂