My main Mac can't run Sonoma without OCLP and I'm perfectly happy on Monterey for now, so I will skip.
I already have RSyncOSX, which after quite a bit of Googling and digging seems to be an older app by the same author.
https://github.com/rsyncOSX/RsyncOSX_archived
As opposed to the new:
https://github.com/rsyncOSX/RsyncOSX
Before that, I used to use ARsync:
https://arrsync.sourceforge.net/
https://www.bartbusschots.ie/s/2006/11/26/arrsync-an-rsync-g...
It was, as I recall, nicer still but it's no longer maintained and the x86-32 binary no longer runs.