personally, when I see birds that "require" double breeding, I wonder which would be preferable... IMO, you are NOT going to have a flock of roos around, but you will have a flock of hens. so IMO it's the hens that need to display the variety to their best. LOL
in the case of the colored dorking, i'm planning (someday when I have breeding pens finished and the predator issue under control) to start working with them again, and see if I can 'reengineer' the variety to meet sop somewhat, as well as breed true. in this case though i'm going to work on a roo that breeds true and whatever hen matches him.