I have done it! Just for fun because I wanted to see what would happen haha. My giant Brahma rooster over my tiny blue silkie hen = light, larger than silkie, smaller than standard chicken, with black skin, 5 toes, and a fluffy hat. She has smooth feathers, not silkie feathers. Prone to broodiness. Egg is light beige, a little on the smaller side.
I tried to hatch 4 eggs, 2 of them died in their shell, fully developed. This happens sometimes, but I'm not sure if it was maybe because the chick outgrows it's tiny shell before it can hatch? Anyway, 2 hatched, one was dark blue and the the other one was yellow. And so, so tiny! My dog ate the blue one unfortunately (oops). But the yellow one turned into the little white hen in the picture. She's fairly hideous but I love her