I have never understood the reasons for the full 180 degree fan wing on the Comparadun. I get why it needs to be pointing out to the sides of the fly for flotation and to imitate legs, but don't get the reason for it to extend all the way across the top. To imitate the wing? Mayfly wings are not oriented that way. To aid in flotation? Hopefully, the middle part never touches the water. It would also seem to put more weight in a place that would make the fly less stable on the water and make it more prone to be blown over and blown around by the wind. Easier to tie, maybe, than splitting the wings? What about tying them as usual and then just trimming out the middle part that would seem, at least to me, to make them more top-heavy than they need to be. That would be pretty simple.
I have seen a couple of split wing CDC Comparadun tying videos but never a split wing deer hair one, and with the lightness of CDC it probably isn't as necessary to eliminate the center portion of the CDD wing as it would with deer hair. And before I get attacked by the Traditionalists, I understand it would no longer be a true Comparadun. I also know it would look much more like a deer hair spinner but without the wider silhouette of the spinner's wings.
I'm sure I'm missing the reason for that part of the wing being there because I don't own and haven't read all of Hatches, so I need your help understanding.