>>63792212 (OP)One overlooked use case is probable cause.
If something happens at your home prompting a police response, common SOP is to do a safety sweep and secure any unsecured weapons. This doesn't involve prying open safes or locked cabinets, but any gun left out in the open or an unlocked gun case is liable to be confiscated.
I've seen three cases where this really backfired hard on the gun owner.
>BurglaryOwner away from home. Burglary happened, automatic alarm went off. Security patrol company and police responded. Police did sweep and found a Colt SP1.
Homeowner lives in CA and never registered it as an AW. When he came to the police to pick up his rifle he was charged and arrested.
>Domestic Asian techie renting room in house. Homeowners are a bunch of violent crazy degenerates. Techie spends all his money on expensive gucchi guns and tolerates landlords because of cheap rent. Huge DV happens, neighbors call it in. Police sweep the whole house and find a fuckload of guns under techie's bed. Seize everything. Turns out some of it isn't compliant.
Techie who wasn't even involved in the original DV situation charged and arrested. Gives up guns, becomes nogunz4lyf in plea deal.
>Disturbance Some idiot launching fireworks starts a fire. Police investigating it see open back door on house, assume it is involved somehow, homeowner isn't present. Sweep, find unsecured firearms.
Turns out homeowner not involved, firework idiot was somebody else, left sliding door open because it was a hot night. But by then all of his guns had already been "destroyed" because PD "didn't have room to store them".
Homeowner later gets investigated because one of the "destroyed" guns turned up at a crime scene.
All of those cases could have been prevented by a $100 stack on gun cabinet.