I am not sure having extra large elevator that can hold 2 aircraft at once is necessary a significant advantage.
it directly weakens hull structure by requiring larger hull side cut outs. It directly reduces deck parking area.
it impose further constraints on how deck snd hanger arrangement by requiring area around the elevator leaving room to maneuver 2 aircraft on and off the elevator.
It seems cycling singke aircraft elevator more quickly is a better solution that making elevator bigger. modern computer controlled elevator mechanism ought to allow the elevator to reach higher peak velocity without to much acceleration or deceleration at the end of elevator travel.