I am processing some red broilers, and langshan roosters tomorrow. When they get big enough, or start to crow, or are mean to the girls they get frozen. I do not see a problem if your processing is flexable.
I agree if you're flexible with butchering times, you could do one of the slower broilers. they're still harvested pretty early, usually before reaching maturity. And, if one does happen to crow, off with his head
some folks do dual purpose birds on this same schedule--crowing = butchering, but I think you'll have a less than satisfying carcass if you're doing it for meat, not just processing excess cockerels.