The aircraft will float if you have to ditch, even with the doors open. Given that it’s a pressurized cabin, creating a sunroof as you suggest, just creates another potential point of failure. If you have to ditch you will keep the doors closed until you are ready to open them. We are going to have a cord cutter on the chute to discard it after splash down so it does not drag and flip the aircraft. You will still have the straps and therefore a way of hoisting the aircraft onto a ship deck.