Just a fair warning: those collars have killed many cockerels/roosters. I would rehome him so he can have a normal life, which for a male, includes crowing.
It's instinct to roost high. It's a prime location. Lower ranking birds will be forced to lower locations.
It's one of the reasons I have one roost height for all.
This is factory conditions and extremely overcrowded. This is the reason factory birds are debeaked in these conditions. They will literally peck each other to death because they are so overcrowded.
The nest boxes are not to be included in the floor space per bird planning.