The optional window on the driver’s side is good for security when boondocking with the top down. It is desirable to be able to see out in all directions.
Ventilation is pretty good with FWC/ATC style campers. Air conditioning seems to be rare, so good ventilation is important. In the southeast, where I live, there are plenty of hot humid nights when it is difficult to sleep without air conditioning. Roof air is out due to the weight. A small window unit would probably fit the rear window. If possible, I would want one mounted in such a way as to allow it to be retracted when not in use, thus keeping the exterior profile stock and clean.
Maybe there are pictures in WtW Forums of air conditioners installed in FWCs utilizing that rear window? Anyone?