I think that is being pretty optimistic. The bumpstock ban went into effect in 2017, 5+ years later, a court has finally concluded that the ATF went beyond its authority. On this issue specifically it couldn't be more clear, the ATF quite obviously redefined a legal term - yet it still hasn't 100% been put to bed. There will be at least one more challenge to the matter... check back in another year.
Yes, today's SCOTUS is a lot more friendly to 2A issues, but time and again they have declined to take valid gun cases, refused to wade into the murky grey areas, and limited the scope of their decisions. I'm not holding out any hope that they overturn the NFA.
Sure, wait 60 days - makes perfect sense and I will likely do the same (got to get my trust set up anyways). But at 120 days, my advise is that you take one of the options outlined. My only concern is that the legal challenges and republicans are going to screw up the best option available... free tax stamps.
Federal courts and the Supreme Court operate under a doctrine of Constitutional avoidance. In other words when an issue can be properly settled without interpreting the Constitution, they settle it on administrative law or procedural issues and don’t wade into interpretation of the Constitution. You’re calling that “limiting the scope of their decisions, but it’s how the Supreme Court has always been run. It provides for greater stability of the Constitution and the Bill of Rights over the long term and insulates against radical changes by a far right or far left supreme court.
In the case of pistol braces, there are several administrative law issues that can be used to throw it out. And the second amendment issue, and Constitutional avoidance is the carrot to throw it out on those grounds rather than wading into the larger 2A issues.