we should ALL be using more use of group tags in the manifest. In Jean-Baptiste's (you know, Google's own lead project manager) example he trimmed down to from 8.5GB to 3.6GB with some simple group switches to tailor for his build environment and target
I wish you would make a video. I have the attention span of a gnat :P
Thank you for writing this all out, though. I'm still trying to figure out how these projects come together. Maybe the groups thing will help you as well. I'll keep this thread subscribed so I can document anything I come up with.