So doing a test with a system that can’t even come close to moving air like an engine (even a flow bench can’t duplicate that but his little vacuum or whatever is ridiculous) and isn’t even close to what the filter sees when running.
The interesting thing about changing test pressures and using as much depression as you can (or...reducing the depression when sorting out flow issues) is air doesn’t behave the way one would think it does most of the time. It behaves like a liquid, except it’s compressible!
So yeah, no air volume and very low depression means his test is meaningless for the most part.