that hole is like the tunnel of a non-transverse drivetrain. One of the reasons all exotics have it..the tunnel, not the hole. the tunnel where the driveshaft goes.
the middle of a belly pan (the very sqaureness a car revolves around for its precision) gains different engergies and physics at different air flows and temps. The tunnel and driveshaft in a normally mounted drivetrain aid in the peace of the body, as well as a bit of the hole you drew. I am no engineer, but I am a car rebuilding lunatic speaking my own language. this hole you drew exists for normally mounted engines. One of the silent and invisible reasons it is simply desirable by more than hotrodders, it creates and maintains comforts not many mention, it cannot be described. It is called physics. The drawback to the tunnel, is when it ends. It is always before the rear end and stuff immediately gets hung up on the sides..this is the silent drawback to normally mounted engines..the rear end gets ripped apart sometimes in a few short years (like all subarus known to man) and embarassing steel breaks like in an old dogde dart..yes the cars killed themselves with physics, the tunnel and energies of elctrical, heat and chemistry explode out the other side of the driveshaft tunnel at the back end and underneath the car.
This problem goes back to over 20 years ago for me, a a 1978 delta 88 I drove broke both tail ends of the frame...I have been analyzing ever since. The most comfortable cars ever. non-transverse is my vehicles for the rest of my days. big or small, they are simply beneficial, the hole through the middle of the car is close enough with the tunnel and a driveshaft.
the height of the hole through the car, its like you are humoring a hinda civic with a brick wall called a vtec engine in front of you. The compression of keeping it under your feet is another benefit for you and the body, the hole is going to find something nasty on many occasions.