Syncthing by itself only logs to stdout. Systemd, runit, etc can pick it up and forward to syslog though, and of course syslog itself can filter out and separate stuff if you like (it’s what it does). 
Syncthing by itself only logs to stdout. Systemd, runit, etc can pick it up and forward to syslog though, and of course syslog itself can filter out and separate stuff if you like (it’s what it does).