There are genes that are simply recessive that can linger and become problematic, because once they are seen, they are established. Then there are genes that are not purely recessive, but are a compilation of traits that can be problematic. These things are strain specific, so it is helpful to discuss with the breeder what problems he/she has dealt with. Usually there is nothing to be concerned about, and you find these things in projects and in birds that have become too inbred. The more information we can gather from a breeder (both good and bad), the better. Over time, you will learn the right things to ask. Most are helpful. Most real breeders are not trying to make a profit, and they will be honest and frank about any problems. If there is any. Challenges are not problems. Every strain has challenges. If we do not believe there is, it is because we do not know them well enough. Don't worry about imaginary problems. We can do more harm in the worrying than is done by any real problem we might encounter along the way.