I'm the guy who made the "how to cut a neoair" video. Before I cut it shorter, I used an impulse sealer on the bottom corners below the cut to see if it could be sealed with heat. It bonded right through the baffles and held together. However, I did not air test it afterwards. When I finally did cut it, I saw the complex baffle geometry and have never recommended trying it in fear that it would cause permanent damage.
However, if you are "willing to experiment", than I say go for it. It may require some funky cutting of the interior material but give it a try and let us know how it goes.