If you have a server and like provisioning stuff, do yourself a favor and make a Nextcloud. You can run it off pretty much any hardware made in the past 10 years, and you straight-up don't need to deal with asinine workarounds like this. It's just like the old days, you and a WebDAV folder, as God intended.

If you can't set up a server but still want a good sync solution, use Syncthing. It's a decentralized solution that doesn't require a main server, and lets you create incredibly intricate sync solutions.