Legally owning NFA Items does not require you to waive any of your 4th Amendment Rights. No LEO my enter your home absent Consent, Warrant or Exigent Curcumstance. One of the most quoted Top 8 NFA myths.
You are required to produce the NFA weapon for inspection in a reasonable amount of time at the request of a Federal Agent. You are not required to allow a federal agent to enter your home, search your property or papers. I own NFA items. I have never been visited, and I expect I never will, buy an ATF Agent or any other federal agent.
I am sure you are right....
But, it does give the big boys up in DC a real handy list of places to look if they ever decide to go whole hog and confiscate.