I believe that if you keep your roo up later (with light) he will sleep in. Mine does.
I have the most wonderful Serama roo and he has a great 'cage' - his house - in my basement. I keep a light on down there in the evenings because I do some work down there and also have exercise equipment...and my wood stove is down there. The light stays on till about 9:30 or 10pm usually. He will go up on his roost somewhere around 9; rarely earlier. Summer time it's about the same.
He NEVER crows before sunrise. In summer, it's earlier, because sunrise is earlier. In winter, (lately) it's been around 7:30. It's rare that he wakes me because I'm virtually always awake before him.
AND - I have 2 full-size roos outside. They go in their houses to roost just before dark, and they begin crowing around 5am or so. Earlier if they hear some animal moving around outside. My Serama roo (inside) NEVER starts crowing just because they crow. He crows only at sunrise...and since he's in the house, he's quite audible. Yes, he can hear the ones outside perfectly, and does not respond until he's ready to crow!
So I believe you might try the light because it should work. As to whether or not your roo will crow when others crow...it's up to him.