Your talking about 'feeling' wind through the membrane, not just a few bubbles coming through after a significant amount of pressure is applied. Even at 1 cfm (which is way more than eVENT would ever allow) you would have to really concentrate to feel this amount of air.
Try blowing through Polertec Powershield. You do feel your breath (at least I do). This is at 6 cfm. Now try blowing through eVENT or Windstopper. No breath is felt. Hmmm.... Air permeability is not in the equation for eVENT. I would acknowledge that a very tiny bit of air is able to help dry out the membrane, but no way is there wind or air coming through that can be felt. Something is playing with your mind.
I've read all the articles you've read and checked out all of the online resources available. I've also got some inside data from Westcomb where they've gotten it from eVENT. Their livelyhoods depend upon the accuracy of this data. They also do inhouse tests on the fabric before using it. They have told me, without question, that eVENT is completely windproof.
I stand corrected on WindPro. It was a total guess, but my point was that materials such as Polartec's WindPro are designed to allow air to pass through it to allow it's air permeable nature to help keep the person comfortable in certain situations. WB-400 is designed to be far more windproof, but allow for a tiny bit of air permeability. eVENT and Windstopper are absolutely windproof.
For windstopper, go to the windstopper website where you will see that Gore claims an air permeability of no more 5L/mē.s (or equivalent in imperial units) (watch the movie)
They also claimed that Windstopper is 'absolutely windproof'. After watching the video, it showed Windstopper settle at around 2.1 l/mē (compared to 740 l/mē, or 26.1 cfm, for standard fleece). This converts to 0.07 cfm. That, in my mind, means that wind can in no way be felt through the membrane. I would dare say that this would be the case for eVENT as well in that the two membranes are so similar. Even if it was 5 l/mē, this would convert to only 0.17 cfm.