I’ve heard traveling with a flare gun checked in your luggage allows for standard lock usage, which will require you be present for bag searches (at lease domestically, US). Not what you are asking for but a cleaver ‘hack’ non the less.
He makes a great case for keeping your laptop with your gun as the only way to guarantee its physical security.
[0] https://www.lufthansa.com/ba/en/sports-baggage [1] https://www.pewpewtactical.com/international-travel-firearms...
But can't they break it off without you present anyway?
The Royal Family having full gun rooms is ok and a tradition but the blebs even having access to a basic weapon is “problematic”.