Hmmm. Good question. I don't think the beard and muff genes are as dominant as the blue egg gene. So perhaps that is the feature that is lost most quickly when you cross your Ameracauna/Auracuana with whatever other breed to produce the EE.
EE's are mutt chickens, usually of americauna or auracauna stock (they both carry a double blue gene) crossed with some other breed. In the resulting offspring, the blue color gene is closely linked with the pea comb. If you want the seafoam green eggs, that would be a light brown layer crossed with an EE that has the blue egg gene. And to get really olive eggs you'd want to cross your green egged EE again with a darker brown layer. So... to get a pink egg, you'd want to cross say a leghorn (white egg) with something that lays a brown egg... say like a barred rock or RIR. (Your EE's with a single comb will likely either be brown or white layers).
I bought a group of EE chicks recently and they look good so far with pea combs and most have colored legs or are developing colored legs. But as far as I can tell none have noticeable beards or muffs
