I remember seeing on one of the longtail groups on facebook that somebody several years back tried mixing Phoenix with Silkies to do it just out of curiosity but the tail never got very long because silkie feathering is too brittle.
Also, non-molting birds are extremely difficult to come by, I can literally count the number of breeders on one hand who have proven non-molting fowl in the US. Just for clarification, Phoenix are not non-molting, the only birds in the US that could possibly be non-molting would be a select few long tailed birds from the Hyde line and David Roger's line (and he hasn't sold to the public in over a decade). Non-molting traits also have to be tested for, like a previous post pointed out they can be easily lost permanently in a few generations to outcrossing or simply not testing to maintain the trait in a line.
