I haven't used ERC either. I remember quite a few over the years that have been successful. I wouldn't go too highly stressed, unbacked as they can blow. Make it a bit longer than your usual draw.
As for violating rings, I would suspect you would have more success if the stave has fine growth rings. As ERC tends to break in tension rather than compression, I would be careful. For an ELB I would back it with rawhide just to be extra sure.
You could also try Saxton Pope's recommendation of a hickory backing, for a longbow. He rated that combination highly.