BTW Jet Cash case got me thinking about possible incidents with customs during border crossing. What if they turn their attention to to my Ledger wallet and require me to enter my PIN to check the fund I'm possessing. What the best reaction should be in this case? Would it better yet if I never take it with me on business trips abroad?
I don't think that's possible to do legally. They also don't check how much money you have in your online banking application, right?
What I mean is that they look for how much cash you carry. You can have as much as you want in bank.
And for Bitcoin, that has to be converted into a country's currency to count as funds.
However, let's say you are right and they care about your bitcoins. Do they know what a hardware wallet is? Highly unlikely. But let's say they know. You can enter wrong pin 3 times ("stress because of police") and you recover some other time from the seed. They cannot know if you have 1$ there or billions.
It is best to just take the time to memorize the seed words of your actual wallet. It's not really that difficult. If you can't do that, there are other methods you could use to hide the words in plain sight - for instance you could scatter them within the text of an email or online document in a way that only you know how to retrieve. This way you could reset the wallet each time you need to go through customs. In many countries immigration and customs agents have the authority to search electronic devices. If they ever demanded to see the contents you can then show them a wallet with 0 BTC.