M609, also a good point. It wasn't a test flight as such, but I should have asked the tower to pass on a warning that I might not be able to make 500 fpm. While that rate wasn't actually difficult, it would have reduced my own workload.
And finally, to make it a trio of excellence, yes, DFC, I agree completely. A request to standby wasn't necessary in the circumstances, but in choosing to contact Director when I did, I made my own bed. I could have delayed the call, while monitoring, without incident.