Crazy. Should be all of 10 keystrokes in native SABRE to manually "on" any passenger, with or without any boarding pass at all. And, yes, even if it's a new calendar day from when the flight was originally scheduled to depart.

I can't imagine that whatever fancy schmancy yet dumbed down front-end has been bolted on to SABRE at gates these days doesn't still make it easy for agents to manually on passengers.

Boarding passes are kind of superfluous at the gate.