I'm using Syncthing to keep in sync between a desktop and two Android phones over tailscale, and it works pretty good, but I have to occasionally open the Syncthing app on Android to "bump" it and get it to sync. It's in a git repo (which syncthing handles great even though there are some older posts online telling you not to do that), and on the desktop I can review and "sanity check" stuff and then commit it to ensure it is safe. Overall a good solution.