For a dual purpose chicken, the SOP will describe and call for a chicken with the conformation of a good table bird. So breeding to the SOP and breeding for meat production are going to be the same thing.
Egg laying: it is going to be up to the individual breeder. I think that most of them feel as I do: My breed is supposed to do "thus" and my bird isn't a good bird unless it does "thus". Some of the things that make up a breed aren't easily visible on the show grounds, but to me, the bird must have them or the bird is not a good example of my breed.
My Appleyards are supposed to be a good egg layer. If I have an Appleyard who doesn't lay eggs, to me she isn't a good Appleyard. The judge can't see how many eggs she lays every year as he is judging. But I know she isn't a good Appleyard and I won't breed her.
My Pekins are supposed to have excellent feed conversion and fast growth. If they don't they are not good Pekin, and it doesn't matter how pretty, if they haven't made weight in the allowed time, they are culled. They might grow slowly up to size and win Grand Champion. But they don't get that chance. They are not a good Pekin, so out they go.