Just had first hatch, trying to figure out genetics for crosses

[VRMC]

Hey everyone, I just hatched out chicks for the first time on the 4th and am trying to learn a bit more about their genetics. Specifically, I’m curious about whether or not they can be somewhat reliably feather-sexed when they hit a week old and am trying to find resources that detail the genetics of the breeds in my crosses. All chicks have the same dad, a silver phoenix rooster, but different moms: a cream legbar, splash blue Andalusian, and black Polish with a white crest. I’m thinking that they probably can’t be feather-sexed reliably because silver phoenix chickens probably have a slow feathering rate gene given that they molt so infrequently, but I’m not sure if the gene that regulates their first feathering is the same as the gene that determines feather growth rate later in life. Any advice would be appreciated!