Trying to keep data on a USB drive hidden long term is a losing game is the thing.
If you're intercepted with anything of value what you want is to rapidly destroy it.
This was the big problem I found when I was trying to figure out a secure way use Yubikeys: they're both long term unreliable, and short term impossible to wipe or destroy fast enough.
Literally a printout of 1 time passwords has better security properties in an adversarial situation.
For a storage device what you want isn't a secure store, what you want is a pin pull or switch which wipes it instantly.