I didn't read through the whole page, can do so tomorrow.
The thing is, if you run a short manifold the puls has shorter way to travel, so the exhaust duration might be where it needs to be.
A pipe that slows it down might be a way to go also, the conical manifold should slow it down and the longer length delays it further.
But I don't know how long the onroad manifold are and how they behave, so I really couldn't say...