Unethical chicken breeds?

Hello all, I had a question that I've been pondering for a while. Are there any breeds that you guys may know of that are unethical to keep breeding due to issues? (Thinking similar to ball python morphs, a spider ball python has severe neurological issues due to the morph genes) I have been told that polish silkies are an unethical one due to the higher risks of their skull not actually being fully formed? I'd also put Cornish crosses into the unethical category because while yes used as a meat bird, they grow way too fast and have all sorts of problems from that as well. Thinking of it, any breed that is labeled as a "high egg producer" (Thinking of one's that are bred to lay twice a day regularly, not necessarily plain stronger layers)

Just didn't know if there was anything more than those few that I could think of. I was wanting to get into chicken breeding and I do value the health of the bird and offspring so I would like to make sure that while trying to breed for looks that I keep it as healthy and ethical as possible. I don't think I would ever get into silkies (I've heard many issues with them and just not a bird I am generally interested in.) But maybe polish? But if polish chickens are also a fairly high rate of the skull being missing a spot then I likely won't get into them.