Comment by skozharinov

I self-host syncserver in Docker, it is relatively easy to set up. The main issue is that it would not tell you that it doesn't work, instead it would silently leave a log file in your browser (about:sync-log). Once it is up and running, however, it works flawlessly. You also have to consider that syncserver is unmaintained and uses Python 2, which has long been EOL.