Thanks for adding to the post.... Its fun to try different screw/tire set ups (as long as the ice lasts, sometimes conditions arent good: too warm, too much snow) and then riding on the edge of control. Sliding turns, especially front, I still fight the toe curling! This year for a week now the ice has been great.
My $.02 on your pictured set up: better grip than factory studs, but to push its grip, it looks like it could use more screws if the pictured tire is for front. Also, the tire would have more longevity with shorter screws: I think those screws will be folding over after 5-10 hours. So to me "ideal" ice tire criteria might be : 3/8" #6 sheet metal pan head screws, or longer 7 x7/16" "pan head framing screws". A tire with more and meatier knobs, a hard durometer, and taking frame clearance into serious account. About 250 screws in each, more in front, less in rear. Use a liner like a road slick with the bead's cut out between tube and tire. I pre drill, and take about 2 hours each tire. I hope this helps! I'd like to know how it works....
BTW, This swamp is located not far from CT., about 10 minutes west of Pawling on both sides of 55. There's a 2.5 mile course. Usually we're able to ride under 55, but that is currently moving water and just the one side is open. There's a third medium sized swamp there too. I'd also like to check the "Great Swamp" in Pawling, tho even just a few acres of ice is fine.