When BA uses the A380 on LHR YVR between may and Oct I have been asked to use the Plaza Premium Lounge otherwise the BA lounge when the 747 is used. I will report back and update this thread when I fly out on Wednesday eve. The reply that the lounge lady advised that BA passengers crowd the lounge is interesting as there would be very few Cathay customers there 3 hours before the flight at the time when the BA passengers could nip in for a moment ie for a very short time before having to board.