I think that it would really depend on the circumstances for me. I havent bred yet but plan to make my first attempt at it next season, (with bps). I think that with some abnormalities the snake can still survive and live a happy life. Mild cases of kinking, duckbilling and bug eyes dont always impair the animal to the point that it will not be able to live normally. Like i said, i think i will have to make the judgement when put in the situation. Until then i cant say for sure what i would do...
If the snake only had a mild deformity i would probably post it on here as an adoption, thats not for breeding. I know there are quite a few members on here that never plan on breeding and they just keep them as pets