Thanks @olivier.piasentin! I really appreciate your assistance in digging into this stuff. I was very concerned about this particular issue.
It sounds like Google is reporting them back via the API as having no size. I would like to be able to take a look at raw metadata of one of the files in this state to see what is going on with it, and if we can compensate for it somehow. Since these are work-related and owned by someone else, I’m not sure this would be possible, however.
I am still digging into the Finder extension issue. Catalina introduced odd behavior when compared to previous versions of MacOS. A lot of our recent changes in this area have been done to try to account for this behavior.
One of them, which you already noted, is that the odrive icon in the Finder toolbar will be removed if the Finder extension is disabled and will not be added back when it is enabled again. In previous versions of MacOS it would be re-added, as expected.