and how are you going to prove your ID? you might as well be the one abducting them, and especially if you refuse to use an app to identify yourself... (playing devils advocate here)

most immediate, would be my children would identify me, next one is under the assumption this suddenly crops up as a policy change, such a policy from the start would be a non starter, however familiarity of face would overide the need for what would be plutobeaurocratic requirement.

the really tight one is how to proceed when there is a change of lawful custody or guardianship, because, unfortunately, divorce, and domestic violence happens, and the lag between court order and, notification of custodial reassignment should be close to zero.