The DS loop probably doesn't help your argument at the dealer level as it implies drag racing, abuse, etc.
Softballer77, you previously posted that you have felt a slight vibration that may be caused by this DS. Why would you then try to sell it to someone else to help you offset the cost if a new one. If it indeed has issues and is non-serviceable then it needs to be scrapped plain and simple. As far as the warranty is concerned, I would think Ford would take care of it. The only reason that I could see them denying it would be if they thought whomever did your gear install possibly damaged it when it was removed and replaced.
I too run a '14 cf ds in my '08 KR. I was told by many people that a ds loop was not necessary. In the event of a failure the cf shaft will simply turn to fibers, thus not damaging the tunnel. BTW, if you want a replacement or spare '13/'14 shaft Shelby sells takeouts pretty regular on their Ebay auctions.