The EVOD heads provide the tighter draw because the air tube is a smaller diameter. Having said that, the exterior diameter is also much smaller than the KPT air tube which I believe contributes to the KPT leaking onto the battery more. So I'm not convinced the EVOD heads are "just as good" in the KPT. I dont think you can put the tube from one head to the other head as they're different diameter tubes. Haven't tried though.
As far as the draw, it does help the draw to stick the tip of a toothpick in 2 of the intake holes. Others have wrapped a sewing thread around the post a few times, just above the threads. Personally, I'm wondering if the toothpicks were also contributing to the leaking I was seeing.
If you're on an EGO or Spinner, with the provided collar, you can wrap your index finger around the back, sealing up 2 of the channels, and push the button with your thumb. This will at least demonstrate the difference in the draw.