Well, I have some limited experience with this. So far, I have only crossed Tomarus with Ponapes.
In case you're not aware, Ponapes are a very rare breed of Oceanic Rapanui fowl. They come from Micronesia and are the result of seafarers scattering the genes of various type of Jungle Fowl across the Pacific, including Greens, Ceylons and probably Greys.
Hence, I've had some unusual outcomes given that Tomarus come from a similar linage. I've seen some crazy genes matching up. I've had crests, polydactyly, feathered feet and some beautiful long clear crows; even though neither parent has crests, polydactyly or feathered feet. It's crazy stuff that only has occurred when mating my Platinum Saudeleur Ponape to his daughter that is half Tomaru.
I don't have any idea what happens when you mate one to a more ordinary chicken. I'll let you know if I find out.