If your purpose is behaviors, process whenever the behaviors tell you to. You get what meat you get, likely not much.
If your purpose is meat then the longer you wait the more meat you get, to a point. I personally don't butcher my dual purpose cockerels until at least 16 weeks with 23 weeks my preferred age. Others have different personal preferences as to age.
As others mentioned their age has a big effect on how you can cook them. The older they get the more you need a slow moist method of cooking in general. As always with chickens there is an exception. Pressure cooking is moist but not slow. I prefer mine baked at 23 weeks but there are many other ways to cook them at that age. No matter the age the bones plus the parts you typically don't eat like the neck and back make great broth. If you don't eat the liver your dogs will love them.
I don't know how practical this might be for you, but many people separate out the cockerels if behaviors become a problem and keep them in a bachelor pad. If there are no females to fight over they generally don't fight that seriously. If they can't get to the females they can't bother the females. This means extra fencing and shelter plus if yours forage for a lot of their food they can't do that anymore and you have to supply their food.
I raise my cockerels and pullets with the flock. Since I hatch mine sometimes I have more cockerels than pullets, sometimes the other way around. I typically hatch around 45 chicks a year. I have a lot of room, a big coop, two satellite shelters, and over 50 square feet per chicken outside when they are crowded. They can be outside all day every day. I think room is important.
The cockerels do bother the pullets, force mate them, but the pullets don't get hurt. Others have had pullets get hurt, it is mating by force. The cockerels fight but only once in all these years have I had one seriously injured. He died. It can happen. About every three or four years it gets rowdy enough down there that I separate many of the cockerels out and raise them in my "grow-out" coop and pen until butcher size. To me most of that behavior is chickens being chickens, but even for me it can get too rough. For many people that can be really hard to watch. Go with how you feel.
I certainly agree with cull as you go. They do not all mature at the same rate. Typically the early maturing ones grow faster and act up earlier. To me it's the most efficient way to do it.