I love all the instances where it says, we will not do this or infringe in this way... unless it is a matter of national security, which we don't have to disclose to you. So basically, do what you want as long as you write it up properly.
And this part: 5.3 Review and Handling of Passcode-Protected or Encrypted Information 5.3.1 Travelers are obligated to present electronic devices and the information contained therein in a condition that allows inspection of the device and its contents. If presented with an electronic device that is protected by a passcode, encryption, or other security mechanism, an officer may request the individual's assistance in presenting the electronic device and the information contained therein in a condition that allows inspection of the device and its contents. Passcodes or other means of access may be requested and maintained for the duration of the search if needed to facilitate the examination of an electronic device or information contained on an electronic device, including information on the device that is accessible through software applications present on the device that is being inspected or has been detained, seized, or retained in accordance with this Directive.
I had thought (and Supreme Court ruled) you could not be compelled to unlock an encrypted device, which is why I always powered mined down before crossing. That goes against the obligated to present devices in a condition that allows inspection portion.
Does that apply to non-citizens? If a CBP officer doesn't like you as a non-citizen, like your lack of cooperation during an interview, they could just deny your visa and your entry into the US. If you're a citizen, they can't deny your re-entry. They can delay you for however long and ruin your day and even keep your devices, but you get to go home.