The FAQ is very informative. All this info is basically available in the original post but only from VERY careful reading. No kudos to be given out there. It would have been better for sure if a) there was a heads-up for folks and b) this FAQ was up front and center from the start.
ONE THING missing from the FAQ is the delete file situation. In finder, even though all my files are "hydrated" or whatever in the sync root AND cache on my local system drive, deleting from Finder gives a warning of complete deletion, i.e. bypassing the trash folder -- and in fact does. The only way to retrieve is to go online to one drive.
For some reason, while using Cocaotech Pathfinder instead of Finder (whether or not Finder remains running), for me, deleting works fine and a delete file goes into trash, and can be command z undeleted with no issue.
Why??