> Generally seen by whom? Do you have a citation for this claim?

By border security. Citation is having worked with ITAR materials in the past, and thus having been required by law to carry clean devices. I had a letter saying my blank phone and laptop were normal. (Only had to use it once, because I was only asked to unlock once.)

> hard time imagining how one would go about telling the difference unless it's a current year flagship smartphone

Any expensive device that doesn't appear to have been purchased for that trip that has zero communications, contacts or other items border security might be curious about will raise eyebrows.

Side note: I still recommend wiping devices and restoring on the other side. But that's quite different from this being best practice. Buying a burner phone is, though that's less and less feasible as we integrate smartphones into our lives.

I thought it was obvious that this is what I was referring to. It’s interesting that people don’t see how traveling with wiped devices sends red flags.

I wipe and restore.

But I have been questioned twice about whether I plan to sell the devices (they didn’t believe me in either case) and one rather unkind border professional I am pretty sure took me in for further questioning because of the blank phone.