So now the interior construction is
The exhaust holes are the line on the left. The v-shape/wedge of holes on the right are for intake.
I ran the ventilation system and nothing was happening. This meant the air in the fan chamber was simply recirculating and would eventually overhead the fan and burn up the unit, while the lighting system sat and fried the box. You guessed it. Now we have the third time we have to take apart the plenum box (good thing we used wood screws). The throat of the beast has to be sealed to the plenum chamber. This will reduce the exhaust noise, but it will increase vibrations in the cabinet shell. I decided to go ahead and tape the throat into the plenum and come back to this problem after I pondered on the possible solutions for the production models.