To paraphrase, when you apply for your NFA approval, pay 200 dollars, send in your picture and finger prints and address, if it takes more than 88 days to be approved, atf will take enforcement action against the gun owner as the atf rule says after 88 days if its an open background check its an automatic denial.
If your paying the tax and sending in a form 4 you don't make the item that is one bought from an ffl and you can't pick it up untill your form is approved.
When sending in a form one you can't make the item until you have an approved form 1 in your hand.
With the amnesty you have the item allready, send pictures of said item along with your pictures, finger prints address ect.. so if not cleared and approved in 88 days( never going to happen in good normal times let alone with millions of new braced pistol form 1s flooding the system)
Then you have supplied the Atf with your info and photo evidence to do enforcement actions and make their case for them.
Your best bet will be to pay for a form 1 and apply for it like you just want to turn your AR or what ever gun you have a brace on into a sbr. Remove your pistol upper and keep it at a different location untill after your approved form 1 has came back. That way you are not sending them pictures of what they consider an sbr before you have an approved fourm
Yes it cost you $200 vs free but it's a much safer way of avoiding problems.