Queenie, the culprit.
Since the crowing was triggered by sunrise I finally figured out that if I could just keep the sun below the horizon until I was ready to get out of bed the problem would be mitigated.
So while I schemed how to delay daybreak I decided to try locking the birds in the dark coop at night. And letting them out when I got up.
It seems to work. They wake up later and once I let them out into the run there doesn't seem to be a need to crow.
I still hear muffled squawking some days if I wake up too late. And I will admit there has been the occasional cock a doodle screech. But overall the very aggressive, noisy crowing has stopped.
And outsmarting a chicken is a thrill beyond compare.