The quality of your birds are so far very, very nice. So much so that I'd like to get a contact from you for future reference.
With line breeding, it is advised to bring in new males from previous generations every 4 or 5 generations. Line breeding is the best way to lock in desired traits, but it is also the best to expose unwanted characteristics and hidden recessive diseases. For this reason, pedigrees need to be kept and close attention to who mates with who should be taken.
And bringing an outcross in so.frequently only serves to mask the undesirable traits in a heterozygous gene pairing. Line and in breeding should be seen as a double edged saber. It not only sets the positive traits but allows negative recessive traits to be combined in a homozygous state so they can be eliminated not masked.
There are only 3 reasons to perform an outcross. Lack of size, lack of vigor and lack of early spring fertility. And an outcross should always be performed with a hen from the desired line .