I have ..... a lot of stuff that is either not 4473'd to me, or was never 4473'd at all. That said, I'll reiterate something I've said several times during the Obama years:
If we ever get to the point that law enforcement is hitting gun stores and looking at 4473's, then going door to door for confiscation, I hope they are thorough. I want those officers to look at ALL of the forms, and cross reference my ammo purchases as well. They should know what they would be walking into.
IMO you will never see door-to-door confiscation or cross referencing of 4473's and guns in the US. If they win, they will just make them illegal and tell you to turn them in. Then wait hammer people for AR's found during traffic stops or from neighbor's tips.
It's a moot point for me though, because between the NFA items, the FFL, and the various activities on builders social media I am on enough lists already. Hell BATFE messages me on FB like every 90 days asking if I'll print them a gun or swift link, or mill a lower for them.