Are you at all worried that breeding back to parents or siblings might bring out other undesired genetic anomalies? I'm not calling you out or anything, for all I know it's common practice in the hybrid field. I guess it would get a little complicated to try and produce the same hybrids using two lines though... I don't have any experience or knowledge of how to produce hybrid strains, it's not something I've ever done. Maybe my initial thoughts are irrelevant