"I have to do this because of country X, you know that they're like, amirite?"
Makes no difference at all in the real world. You don't have to give valid answers, you need to get the guy across from you to not find you suspicious. That phrase is going to put a red flag on you, valid or not.
What? No, who cares about that? Let him find you suspicious, what matters is that he doesn’t access your data. And it is not suspicious to cross borders (esp. US borders) with burner phones. As others have said, it is standard practice.
Definitely.
> Maybe, if your data really is that valuable and a successful border crossing isn't.
Even if my data consisted entirely of cat pictures, it would be more valuable than successfuly crossing the border into a country that actively tries to invade my privacy.
(Not legal advise of course, just observation. Always check with the legal department of your employer, etc.)
After cornering themselves into being labeled an unsafe destination (long overdue imho), the US are gonna have to learn being treated as such.