I'd point out the letter says occasional incidental shouldering (as far as I read it). I take this to mean that if you buy a brace with the intent to shoulder you are still in violation of the law. As I read it, the letter means that if the brace accidentally touches your shoulder you won't go to jail over it, or if you shoulder it intentionally in self defense you are safe. However, if you go to the range and put 200 rounds through it with the brace to your shoulder the whole time you could still be in violation.