He is a handsome, dude!
One of my 4-month old splash cockerels had a big comb like your porcelain (but was sold because of extreme red leakage on wings). My other splash, Leo (@ 4 mos old) has a big comb still developing underneath the crest. It is bigger than Bullets at least. Than I have a beautiful splash cockerel with the single comb. I read a link or post somewhere that "single combed" roosters have higher fertility also. At least between my 3 cockerels one of them will eventually give me some babies.
Why would you want to breed single combs? just wondering. You are going to get a lot of single combs from now on if you do.