I’ve been running the Joplin server for over a year with clients on four laptops and three phones and share notes with my wife and its wonderful. There are certainly quirks and sometimes sync issues but by and large I’m really happy with it. There seems to be one cluster of notes I have that always irritates a fresh client sync and it shows up at 50 conflicts but I work through it. Also my notebooks are huge and the first sync can take an hour. It’s a lot slower than I’d expect.