The rivet bottom flange in the Ti wing stove broke B/C it couldn't withstand a bit (& I mean a little bit) of accidental torsion when I folded it up.
I'd use aluminum from a large baking tin (found in most supermarkets)for the windscreen. Make it's top edge go up to within 1/4" of your pot rim (so you can still get your pot gripper on the rim)
Punch some 1/4" holes about 1" to 1 1/2" apart around the bottom of the 'screen, say 1/2" from the edge. This will give you an updraft which carries heat around the sides of the pot as well as on the bottom.
And make the 'screen a close fit at the top near the pot sides so you trap more heat. But remember, ya still gotta be able to get the pot in and out of the 'sceen easily.
Have fun! Tinkering with backpacking gear is one of life's relaxing pleasures. Plus it gives greater pride of ownership if the tinkering is successful.