Back when I made that list, I got data from bigger producers, biggest data point being 4 kinked animals out of over 40 supers. That’s about as rare as the reported data of getting a female from a male maker banana. Which we also call rare.
I also noticed anecdotal evidence that some people never/hardly seem to have issues and other have a high ratio of it. Seems the particular animals seem to play a factor and not just the cinny/BP gene exclusively. Ive noticed the same with super lessers and bug eyes.