I asked part of this question in the recording and mixing forum but this is specifically the bit about subgroups in the RB mixer.

if i send all the backing tracks to a subgroup can i put one plugin fx on the subgroup channel strip instead of individual channels saving plugin resource needed. would it act like a mini master bus? i'd like to try whether i can globally process part of the mix by using a subgroup.

and if i have reverb on an aux send and return, and route several tracks to it, will the reverb be affected if i send tracks to the subgroup? presumably the aux return sends to the master output bus (as i think a hardware mixer would do) so it would bypass the subgroup which could mean a reverb level at the original track volume setting not a reduced volume if the subgroup fade is lowered. or would it?

maybe i'm just getting too clever for my own good with nothing to do in lockdown...........