Brian, Isn’t there an issue about using timesync on read-only file systems?
I understand that when it syncs time, it writes the data to /var/lib/systemd/clock which is hardcoded, and of course it can’t do if the system is RO.
Also… https://feeding.cloud.geek.nz/posts/time-synchronization-with-ntp-and-systemd/1 appears to be a dead link.
Try Time Synchronization with NTP and systemd
Paul