"Started" state of container

I have question - in which moment is container declared as “started” and another one is going to start - when you have set boot.autostart.priority.
Does lxd knows about for example state of systemd inside container, that lxd “knows” when starting is completely done? I’m just curious about it.
i’m using priority and delay together, because i need some container started (and running (and registered in dnsmasq dns)) before another one - due to name resolution in config files.

I only need the sure when container is started/running, that is registered in dhcp/dns, so another containers should boot up and use their resources via hostname.

LXD considers a container as started when PID1 is spawned in the container.
It doesn’t know nor can really tell anything after that point.