Line breeding can enhance flaws, the first duckbills I saw were Cinny, but I have no definite knowledge of who produced the very 1st... I just picked the morph I liked best & got unrelated animals. It's worked for me so far.
I agree that some morphs have their challenges and each breeder has to determine what they are willing to work with. I love the T+ Albinos but I had worked with another species before BPs that were homozygous lethal. I was able to reduce the 50% adv. defect that most breeders saw down to 25%, but that's still allot of deaths. That's a big reason I got out of that.
Minor defects that I can work around, I'll work with. But kinking- well that's increasing the chance that I'll have to put babies down. I'm hoping the Ultramels prove to be a line that doesn't have the issues that the other T+ do. If so, I may work with them eventually. If not I will have plenty of other stuff to work with. I respect each breeder's personal decisions to pursue the projects they love.