Controlled devices are these which you can start/stop via Astor, i.e. launched by a Starter process on the target system.
The top level however is starting the first Starter instance, e.g. via systemd. In this case, you cannot control it via Astor from the outside. (I need to log on to the VM via SSH and restart the service via systemd in our case.)
Regarding your other thread where I suggested to nest Starter-devices, they will probably show up as “controlled” if launched by another starter, as expected.