The 3rd person is usually booked at a discounted rate, or free, so the package does not apply. You can purchase the plus package either before you board or right when you board. That’s how we did it.
Is it mandatory to use the medallion. My brother-in-law is one of those who thinks everyone is watching. He refuses to allow access to his photos and camera. Does he somehow bypass this? I apologize if this has already been asked.