I added a knockoff of https://www.youmagine.com/designs/laminar-flow-fan-plate to straighten out the airflow, and then made three separate ducts to feed air out around the hot end instead of one big duct with three spaced holes. There's enough flow that I may have to kick my hot-end temperature up a big, and no back-breeze on the other side of the fan, as there was for the earlier version. I was lazy with the Openscad, so you'll have to trim the screw holes and the duct openings to make it fit. It would be relatively easy to modify the code with some difference operations around the outside and at the tips of the ducts.