It seems unlikely that the ten minutes would make a difference in your ability to make your flight. I was able to book it without having entered any flight information, hopefully that won’t cause problems later. I just figured that if i wasn’t using Princess Air, flight time wouldn’t matter to them.
The wording in the tour description is a little funny, though, I’m not sure what they’re trying to say.
Passengers with Princess Air should book a customized air flight ticket to be sure they can participate on a tour the day of disembarkation. Passengers without a customized air flight may not be booked on a flight which will permit them to participate on a tour on the day of disembarkation.