Yes, in some cases(in the cases where the endpoint(resources) is not discovered from its default Ironic discovery, but configured in the pipeline yaml) the resource_id would not be the UUID, but the endpoint(resource) ip/hostname. Because in that case, those physical machines are not managed by Ironic so we can't get the UUID for them, unlike those machines managed by Ironic in which case can have have a UUID resource_id
Yes, in some cases(in the cases where the endpoint(resources) is not discovered from its default Ironic discovery, but configured in the pipeline yaml) the resource_id would not be the UUID, but the endpoint(resource) ip/hostname. Because in that case, those physical machines are not managed by Ironic so we can't get the UUID for them, unlike those machines managed by Ironic in which case can have have a UUID resource_id