This whole mess could be easily resolved by getting rid of the ridiculous and unconstitutional NFA.
Aside from in Hollywood gangster movies you rarely see criminals hiding short barreled rifles under their trench coats and it really isn’t any more difficult to hide a long barrel rifle under one anyways. Anyone who wants a small concealable package could just legally get a bullpup or do what all violent criminals do which is ignore the laws and carry whatever they want.
The NFA has its roots in Prohibition where government sought to ban weapons it believed were being used by organized crime that supplied the public with the alcohol it demanded. Prohibition ended, but the public safety laws and regulations and bureaucracies like the ATF lived on and grew for close to a century with no inquiry into whether the laws were still relevant.
How is the public safer with a ban on short barreled rifles?
Whenever government declares war on alcohol, drugs, poverty, etc, millions/billions of taxpayer money and printed money will be spent on enforcement and individual liberties will suffer.
I suspect the NFA was as effective at keeping weapons out of the hands of criminals back then as it is today.
I also suspect the politicians back then used the same kinds of Hollywood movies and false propaganda from anti gun groups to inform their decisions as todays politicians do.