Awful expensive for pennies worth of plastic. OP, how long have you had it? Does it get your camper cooler than without, or does it simply get to your desired temperature sooner?
The video is greatly oversimplified. I'd have to guess that the majority of turbulence in the system is from the narrow ducts and the poorly designed turns and 90 degree vents.
One of the benefits of the AC dumps is that on a hot day you can open the dumps and cool the main living area more efficiently than the vents that are in the minimally insulated ceiling, baking in the sun. I'd be worried about getting rid of that advantage... but I'm curious about increasing the cooling ability overall.