I never doubted your combustion chamber comments if that is why my name is in brackets? I just like to see what has been done and works.
Haha... "little known fact". This guy must have just learnt it. I am sure the guy is very smart, but that is a bit rich. The air doesn't stop at the port so that is obvious. But he is correct about the pressure thing which is why Vizard recommends the variable pressure flow bench.
The influence of exhaust to inlet port has been understood for decades, but perhaps not the finer details which like everything fluid dynamics related may never fully be. The so called rules of inlet to exhaust ratio only apply if you are using the maximum valve space allowable and are still based on some very old experiments from Charles Taylor (despite some claiming it as their own). So the post is right there too. Making an exhaust valve smaller (unless there is something horrible wrong) is not going to make you faster and if your exhaust is flowing at least 60% of your inlet your not giving that much up. But, if it is flowing 90% you are not either unless you have hammered the port in the process. I think that influence of exhaust tunning is often overstated and Sly's post also suggests a hint of that.
The very last point made in Sly's post is the main point, why do we test at a constant arbitrary pressure drop? Because it's easy and gives us a good starting point to work with. If you were to design a new head using CFD, you wouldn't do it, but at least it gives you some information to work with.
It is a good post with some good points, but he is still talking in black art.