It should be very difficult to ever change anything in the SOP. Otherwise, the latest fad and hippest group will change the SOP to fit their birds instead of breeding birds to fit the SOP.
I have a question, I have seen alot of Wyandottes who stand with their wings dropped. Could it be split wing? All of mine carry their wings correct, but I have noticed a line that I have seen tons of pictures of and when I asked someone they told me the birds were just tired. I don't think...