For what it's worth I've got a couple of Royals that are ravenous eaters and have both eaten defrosted chicks over the years - no problems .. They'd take two or sometimes 3 at each meal . All warmed up with the hairdrier .
Day old frozen chicks only cost 10p each ( 12 cents ?)
I don't keep them in nowadays ..
They're just something I tried a few times .. usually when I'd read an article on varying your snakes diets with mice / rats. /chicks and varying the period inbetween feeds and also giving them random sizes .... supposedly to replicate their feeding in the wild !?!?