I like the Satanists for the purposes of showing/challenging legal exceptions for religious beliefs. Unfortunately a big hole I see in this logic is the notion

I like the Satanists for the purposes of showing/challenging legal exceptions for religious beliefs. Unfortunately a big hole I see in this logic is the notion of "reasonable accommodation"; that is to say, what is considered a reasonable accommodation would be influenced by the majority religions. So, certain opinions on certain medical procedures would be considered reasonable, while others wouldn't be, and a heavily-Christian-influenced cultural notion of reasonability would of course be biased towards Christian religious beliefs...