Hi there Veet
I think it's a good idea to contact whomever it is privately and educate that particular breeder about it. I think it is especially important for the costume cats because people sometimes do think the traits of the costume can pass and that is even more likely if a cat is labelled as having the traits of the costume in some manner. I think the "+1" has become a matter of individual taste. It isn't something I do as I find it misleading to suggest the cat can have more than 9 traits or state size as extra plus trait... it cannot be lol. Cats have 9 trats max and that is how it is, but for some reason some people do put this "+1"