Yeah an hour is definitely best. Haha yeah that guy in the parachute room is a champ, he will do everything he can to sought you out. Also if the instructors see you sitting in the lounge with your helmet on they will know you are serious about getting a spot. They might laugh, but they will know!
Another good tip for this is to do chair flying with partners in the lounges (without the helmets, only do that once lol). Set up one of the big ct4 cockpit printouts in the front of one of the lounges and take turns in partners chair flying and critiquing eachother. The interviewers actually bought up how impressed they were that we were doing this, which just goes to show that the instructors are always monitoring what you are doing.