It would be useful if the Metadata API for an instance could return the running state for that instance as part of it's response.
As in if I am a Metal instance, I want to be able to get "state": "powered_on" or "state": "provisioning" from my Metadata API.
This would let automation pivot based on the platform state of the box, as in "If I am still in provisioning state in the Metal platform, wait until state is powered_on before performing proceeding.
Exposing it through metadata dramatically simplifies the act of getting the answer needed as opposed to querying it via the public API