Well, after getting lots of advice (Thanks everyone!) and after a bit of struggling and testing, I believe I have completed the tweaks to my 2021 workflow. The thing that finally brought all of this together was insync, which after several days of testing is working flawlessly in syncing Google Suite to DEVONThink. And, notwithstanding my tweaking, I even managed to get a chapter written in my book this past week. 
All in all, I’m pleased with where I’ve landed.
