Greg: My confusion continues, because when I had my windscreen reasonably tight, it was barely covering the base of the pot. On the Bobcat above, the holes are cut in the screen high up, and much of the pot is covered. All else being equal, my system would have had more breathability. The only way I can make sense of it, is that the stove used by the Bobcat is not a huge oxygen sucker (like the SuperCat is known to be). I'm fairly certain my SuperCat would snuff with a Bobcat screen.
I suspect that slower burning alk stoves have two advantages: greater fuel efficiency, and less of a need for air quantity (allowing tighter, more windproof setups).
Dale: Scoop shaped vents seem like a winner of an idea! The windscreen wouldn't roll as tight, but neither would you have to worry about wind blowing through the holes as much (if at all). By "scoop shaped" I assume you mean louvered vents like this?
EDIT: just realized what you meant, Dale. You were referring to "crenellated" cuts along the top, like a castle tower.