the fact is also that with 2 parralel landing decks the ship has to have an extreme beam to clear the takeoff ramp on the bow. elevators is going to be an pain in the ass, and so is the hangar. the landing point will be entirely out on the edge of the deck, so the ship moves a lot more over there, and worst of all: I think the increase will not be an double airwing, but only an increase (20% max compared to an ship of the same displacement with an 'conventional' arrangement.)
30 second separation for the conventional deck, so here we get 15-20 seconds..... in which 2 aircraft need to be moved to the parking space or hangar, out of harms way, without getting in each others way. this requires planning and timing, and absolutely no room for error.
fun fact, the hangar would actually be smaller then that of an conventional deck, because there can be no deck edge elevators, the bridge has to cross it somewhere, and you need more elevators for the larger number of aircraft movements.
so, I would keep the conventional arrangement, and use the additional size for more repair and maintenance shops, more stored fuel and weapons and the ability to take slightly larger planes (aerial refueling aircraft and AEW, for example) instead of moving to an entirely different arrangement.)
that said, my own carrier design that is moving through revision after revision since I joined sb is more focussed on getting an as large as possible airwing on an size-restricted hull and deck
going to extreme size is not always the answer to getting 'unconventional'