Them little holes aren't going to make a difference really. We all applaud the innovation, just no need and if completed needs to be done correctly.
He probably has a sliver in the hat area for the air to squeak through like I did before I revised my setup. What would be more effective here would be to place the duct an inch or 2 away from the hat in hopes that Bernoulli's principle works with you to blow more air toward the hat than the duct itself can carry. Without a shroud, the effectiveness will be pretty limited anyway. I tried running street pads with proper ducting on the track and it was a mess, better off with good pads and zero ducting.