Yes, however you are also required to keep a copy of the approved form 1 or in this case submitted form 1 at all time when it’s with you.I believe that the only policing agency for NFA items in the ATF. They are the only agency that you are legally required to produce paperwork if asked.
Would it really be worth it to be a jackals when a cop ask you if you have the paperwork for a SBR just to make a point? They can and should detain you until a atf agent can come and verify your paperwork is in order. Is it a pain in the a$$? Hell yeah it is but it’s also easier to just comply if there’s nothing to hide….. All that just to say life would be way easier without the atf around