Yes, so you found that to which I was referring.

"Travel control of citizens" is something with which the Soviets would be familiar. Quite telling choice of words there in the quoted USC section.

Given the general requirement covered in that section above and the allowances for Executive discretion (good and bad), I doubt we would see this US citizen be prosecuted by a USA/USAA merely for being in violation of that section in the situation of a serious family medical emergency.

The PR nightmare of prosecuting an otherwise law-abiding citizen only for a minor technical violation -- of a legal requirement of which most Americans would be unaware -- in the process of rushing to the bedside of a dying parent is not something the Executive would want given what it may mean in terms of reduction of power(s)/discretionary allowance.