Great links.

Yeah, it's not really a global "I have nothing to hide from any government whatsoever" but more of a "I don't have chat logs about overstaying or smuggling," which is what they're likely to implicitly assume if they've hit the point of searching your phone and you've got some special phone they can't search.

In my home country I would take a principled stance and hire a lawyer, but in the particular case of border crossings to a country you're not a citizen of, seeming like you have something to hide can easily lead to them denying you entry.