He's saying they just plug your USB stick into some gizmo sold to the state, and it's going to find enough to escalate it.
If the idea is that there's no point in encrypting anything on a USB stick, and you just hope they don't look at it at all, sure.
But there is no threat model here that includes "check the USB stick" and does not automatically lead to finding and breaking "hidden" content.
Try to explain how the hidden content would be found? It effectively doesn’t exist until the password is in place. It isn’t hidden, it isn’t connected at all.
I’m no expert but I can imagine a scenario where an x-ray scan can notice an SD card embedded into the controller and flag that for follow-up
SD card the author says was added to offset the cost of eMMC but would presumably stand out as anomalous with whatever AI is classifying the scan