Ahhh, well thats where my expertise on persians falls down a bit! I don't know much about that side of it really, because I've never shown any of mine, nor bred from them. My friend who bred some of my persians was a persian colourpoint breeder, and I've only ever had colourpoints and 1 red solid/self from her.
However I do know that exotics initially came from Persian longhairs crossed with British shorthairs, although now exotics can be bred to exotics or exotics to persians and indeed persian longhairs are used in an exotic breeding programme to keep type, conformation and quality of coat. But I don't know about persian breeders using exotics in their breeding programmes, I wouldnt somehow have thought that was encouraged.