hyperscientist wrote:option #3 may only be there for MIDI recording purposes (and similar). Am I thinking right?
I don't understand that remark. Outputting audio "to regular audio tracks" is the normal way to do it. It's called "using a buss". It's more flexible than grouping as you can send any number of tracks anywhere to the same buss.
I buss all drums normally to the same buss and I also buss other instruments that I think constitute a whole "part" in my song. That way I can set internal levels once within that part, do treatments for this in one place and control volume fades and so on.
In concept Grouping is just a way to send audio to a buss as the group track acts like a buss. It's just the visual layout that is different as well as the group track can be MIDI. Rack tracks are always MIDI tracks.
To me sends to return tracks feel a bit awkward as solution for summing, but it's certainly acceptable.