Don, Geebs, Wynette and anyone else interested:
Yes, Don the Co gene is different on the eWheaten and eb birds. BC's are ER Birchen based and Co does not do the same thing. My point is that there is are correlations between male hackle/ saddle feathering and the genes they pass on to hens. What if eliminating the hackle stripe were a step toward getting some good males and females out of the same parent birds? Not everyone is going to show their birds (and will only single mate), and no one wants to sell eggs that they know are only going to produce decent roosters OR hens but never both. It is just a theory, but it's never been talked about to any length, nor has the affect of hackle stripe on hen offspring been recorded or studied. If everything else about a rooster has an affect on the hens, why not the hackle stripe?
There are unknown melanizers out there, some are recessive and they each act differently, sometimes in subtle, hard to notice ways. We've seen birds with perfect hackle color but with black saddle feathers - this is one example of a type of melanizer that acts on one specific area.
Just putting it out there, just another thing to try to uncover in this interesting endeavor we are all in.