It's worth noting that epoxy doesn't bond well to stainless steel - I don't know why it sticks like sh** to a blanket* to aluminum, brass or plain steel, but not to stainless.
So a waxed stainless screw has to be the best bet to get out. I can testify that brass is a no-hoper in these circumstances - the epoxy bond will always be stronger than the screw slot!
*This is not an offensive term, it is a recognised British engineering term for a really, really good bond. Honest!