Ok I am going to throw an outside the box thought out here. Why is the current practice to place the biz lavatory at the front of the cabin? Could the lav be moved to the rear of the cabin? Thus in the event that an economy passenger does wind up using the biz lavatory they are not walking past all the biz class passengers?
Is there some essential equipment (wiring, plumbing) at the front of the plane that can not be relocated to the middle? Would this set up use more space than the lav at the front set up?