Ever done a 4473? Your background check has all the info they need.What paperwork does the State have? Washington has only recently tried to keep track of semiautos, and I'm not sure they are all that competent. Stacks of forms in a warehouse is no way to keep track of anything.
Just bet one everyone knows. No info ever goes away. It's not "paper"work anymore. All done over the computer. it's been digitized for a long time. They don't run into the warehouse to find you file and then read it to make sure you are not a criminal.
If you've never done a 4473 or other background check for a firearm and you've never mentioned firearms on the internet, text, phone call you might be under the radar. You are here talking to me. I'm on all the lists and now you are too!! Welcome to the fun club!
Universal background checks are just another tool.
With the right request and key words one might even be able to FOIA that info. I've seen more private info released under FOIA.