On Oasis and Allure passengers do not go to the actual lifeboat stations. In fact you really couldn't put everyone in rows at the boats aboard Oasis and Allure. There isn't enough room on the deck area adjacent to the life boats. Those boats are set up for immediate loading with no need to lower them from above. They just open the doors and you walk on. So - the muster stations are inside the ship as Princess has done for ages. On Oasis I was assigned to the fitness center muster area. We were just a few steps away from the door leading out to our boat.
A point for those cruising on RCI - when the drill happens make sure you have your card in hand and visible. The crew stationed along the travel routes will constantly be asking to see the card so they know you are heading in the right direction. As previously stated, there will be at least one crew member at your station with a handheld scanner.
For ships not using the scanners they do search all cabins and public areas and restrooms to find those who are trying to avoid the drill. RCI employees will put a 'cabin searched' card in the door keycard slot. They usually gather them up before the passengers return but on at least two occasions I've returned to our cabin and found these cards in the door.
It's been a while since I last cruised on Princess but it seems to me they called out cabin numbers at the drill and we had to reply with the number of guests in the cabin, and thus the expectation that those people were present. I may be confusing it with another cruise line's procedure.