Hi all,
I know I'm not the first to ask this—Dropbox users have apparently been having problems with it for years now—and maybe there's an answer somewhere in the forum that I simply haven't found yet. Please accept my apologies if so. In the meantime, though, this is starting to drive me absolutely bonkers.
All I want is for Dropbox not to use Smart Sync on my Mac. Never. Not ever. Period. I have more than enough space on the external drive where my Dropbox folder lives for 100% of my Dropbox files to be stored locally, and that is how I want them to be stored. When I need access to a multi-GB video file, I'm not interested in waiting a minute or more for Dropbox to upload it to me, because I'm in a production environment and I actually don't have that kind of time. When I tell Dropbox that I need for it to do LESS work, to stop trying to be "smart," and to simply do what I am asking it to do in every preference/setting I've managed to find, why does it not listen?

This seems straightforward enough, but it simply isn't being respected, and I can't figure out what else I'm supposed to do so that it will be.
I have recently started running an rsync process that clones my entire Dropbox folder, due to other strange behavior (up to and including that entire folder spontaneously disappearing one night and needing to be resynced) that have convinced me that a third form of backup is a business necessity. But that process is fighting an uphill battle, due to the sheer number of files that are simply not there when it asks for them, because Dropbox has chosen to ignore my preferences.
My current plan is to complete this clone, however long it takes (I've been trying for almost a week now), to add a cron job that refreshes it every 15 minutes or so, and to switch my production processes so that they access the clone rather than the original folder that Dropbox keeps trying to be "smart" about. I believe that this will work, but it frustrates me to no end that it should be necessary.
I have found one article that seems as though it might help:
https://help.dropbox.com/installs-integrations/sync-uploads/filesystem-integration#optout
This applies only to MacOS 10.15 and earlier (and Windows), but this machine hasn't been upgraded past that point for other reasons, so it may be an option. This is how it's supposed to work:

However, when I follow the procedure and turn off the extension, nothing actually appears to happen. I am not signed out, and Smart Sync remains engaged in its quixotic efforts to "help."
But even if it did work, wouldn't uninstalling the system extension be overkill anyway? I could be mistaken, but my best guess is that this extension is responsible for more than just Smart Sync and also handles things like Finder integration which I certainly wouldn't want to lose.
Thanks for reading. Any suggestions for what to try next would be greatly appreciated.