No. I don't know whether my setup is typical, but I have one machine that new machines have designated as an "introducer," so each machine eventually learns about the existence of the others. As for syncing itself, it just works. I have a $4/month virtual server running Syncthing, so every machine that's online always has at least one to connect to. Changes typically propagate through that one. But before I went that route, data eventually got where it needed to go.