MJB,
I think that it all depends on the particular aircraft. For example: When I had a 'jolly' in the back seat of a RAAF Mirage in 1980, it was important for the back seat to leave before the front as there were conflicting flight paths for the then Martin Baker Mark Four seats.
I managed to score a flight in a RNZAF Skyhawk in 1981. With that aircraft there was no conflict that I remember. Only the professionalism of the Captain making sure that his crew abandoned ship before him! I think that the same applied to the RAAF Macchi flight that I scored in 1978.
Being then young and more adventurous, I wouldn't have minded being the first Australian troop to score a Martin Baker tie. Bravo Miatamad!