I don't think you clearly answer to my previous question so let me ask again: did you face any concrete issues with delaying the creation of sytemd-timesync system user or not ? Again the final initialization of a stateless system is supposed to happen on the first boot process. So I'd like to understand why this couldn't be achieved or whether it's currently "only" some inconsistencies you're seeing between some systemd-user-* packages and systemd/udev.