I'm familiar with that thread. I participated as user "Clagwell". A cyclone can't cause that weird behavior. It has the same square law characteristic as everything else does at those flow rates. The short overall height and large diameter actually reduce the pressure drop compared to a long cone style.
Check the Laguna short cone curves. Except for a lower stall pressure they're very similar to other cyclones as well as non-cyclone systems.
Again, the static pressure versus orifice size has absolutely nothing to do with the cyclone shape. All of that happens outside of the cyclone.
No, Grizzly just got it wrong.