This was kind of the problem the first time, and people believing that the letters ONLY applied to the person who received them.
Yes, that's mostly true; however, it sets precedence. Something that is looked at strongly in most courts.
Instead of people just shutting the hell up, they inundated the ATF with the same question over and over and freaking over again until the ATF probably got so sick of it and said no just to shut people up.
So now people have been doing it again. Asking stupid questions for "clarification." FFS just don't do it.

shockwaves are good to go

Like I always said..If you buy a brace intending to to use it as a stock, and do so, you have an unregistered SBR....

If you say 'I want a brace so I can shoulder it' = SBR

That's correct. It's intent. Now just having one and saying one day at the range, "hey what if I do this?" is ok. Yeah the results are the same, but it's based on intent. It's hard to prove, but making public posts that you want one to shoulder it, or posting pics of you doing so and saying how you are getting around the ATF (and people did do this) is just silly.