I have no idea what you mean. I just had to set this up once on my parents’ phones and now it works all the time, even when they change networks, no port forwarding or any interaction required on their part. Rsync is a cli that requires an existing network connection between two devices, both online, and doesn’t watch files or create a file version history. It is an entirely different tool.

Not as much as the syncthing apps.

The android development always just seemed… off, idk, I just got weird feelings about it and the fork. So I switched my family to use termux and termux:boot to run syncthing instead, it works fine.