He’s on the food like flies on

then sits by the feeder waiting for meal worm treats. The others eat but I’m worried he’s going to get so big I can’t balance how much he gets compared to the others. I didn’t want a meat bird because I’m not willing to butcher it (I don’t even eat meat). I knew from the start he looked way different in color but he was kinda the same size so I brushed it off.
Op, what are you able/wanting to do in this situation.
The way I see it you have three options-
1) Cull it now so that the other birds can eat and you don't have to worry about it anymore.
2) Separate it within the brooder, and raise it until 8 weeks old. Then cull it and eat it.
3) Separate it within the brooder, and restrict feed so it stops gaining weight. Continue to restrict feed for the birds entire life, and make adjustments to your setup to suit him/her, and keep it as a pet.
If you choose option 3 I can give you some tips. Just be aware, pet meat birds take more time and energy than simply, restricting treats from your over weight laying hen. You have to make sure that the Cornish does no have access to the feeder that the other birds eat from free choice. Though it also has to have interaction with other chickens, so unless you get another meaty and put them in a separate coop, it will have to live with your flock. That means you will have to make sure the other birds can get to the feeder, but it can't. You will have to watch its weight carefully, and figure out how much you need to feed it twice a day. I do like to feed my Cornish X Dooel crumbles, since she scarfs it down very quickly at meal time. You will need to make sure the the birds quality of life is good. This means watching weight, watching how it interacts with other chickens, watching it in general. Not all dieted Cornish X live happy lives, and one may have to know when to cull out of mercy. You will obviously, have to have time to feed him/her twice a day.
On top of that, what if its is a rooster? I don't think that most Cornish X roosters would be able to successfully mate a hen, but I'm sure he would try. This could cause serious over-,eating issues in your flock.
If you think that you can work with all of the above, great! I think its a fantastic thing to take in a Cornish X and keep it as a pet. Just remember that it takes a bit of effort, sometimes more effort than the average backyard poultry keeper is willing to put in.
If you do put it in, than you will be greatly rewarded. Cornish X are so social, and Doodle is probably the most hilarious bird I own. I couldn't imagine my flock without her.
If you decide to go for option three, I'll link my thread and article for you. It had a ton of info, I hope I was able to help!
Good luck with your meaty!