Was on the FAQ for the ATF's efile page ( https://eforms-form1.atf.gov/faq ) checking on the brace info and I saw this:
Now I'm 99.9% sure this wasn't on the FAQ last year when I filed a Form 1. And I remember googling this very question and reading 2 dozen industry sites, silencer shops, even lawyer's pages on the topic and the consensus had been it was ok to let others shoot your NFA weapon(s) as long as you were physically present and close. So ... heads upQ. If I am the registered owner of a NFA item, can someone else shoot my item in my presence?
No. Only Responsible Person(s) listed on the approved registration may have physical or constructive possession of the NFA item.