Just pay for the sync. I used to juggle with git, rsync, inotify etc and other tools

Its one of the few subscriptions where it actually feels like money well spent

I was using SyncThing, and it worked, but any time you have an Obsidian vault open on two devices, or shortly after another, you're always thinking about if you're going to have to clean up a bunch of sync conflict files later. And that mental overhead is not worth saving $4/mo.

The conflicts are never hard: it's like a git merge conflict where you just take the latest of every conflict block.