I have talked to a few people who work with the gene and have produced multiple super animals. From what I have been told, duck bill and kinks can be as rare as 1 in 50 and can be as often as 1 in 2. It doesn't seem to matter whether it is cinny or Black pastel, both are prone to it. My guess is, some blood is just more prone to it or some certain pairs change the ratio, but that is purely guessing. Cinny and Black pastel are allelic with each other, the wobble has nothing to do with anything in this subject.

Black pastel seems to be the majority favorite, but black pastel seems to be just as prone to duckbills and kinks as cinny. I think it's just when you work with dark genes, you want the darkest of them all and black pastel tends to be darker than cinny.

Hopefully someone can chime in with first hand info for you, but I hope that helps