I don't think the traits are mutually exclusive, but it's only recently that people have started breeding thick bordered morphs other than okeetee and reverse okeetee. You see frosting most often in ultra based corn snakes. If you look through the tequila sunrise pictures on iansvivarium.com, you'll see that several of them have frosting and quite thick borders. Heavily frosted and thick-bordered snakes are some of the nicest looking, in my opinion!
http://iansvivarium.com/morphs/?m=te...9c962342f62509