First picture - in addition to running stove slower, maybe cut off the bottom a little so it doesn't go down so far? My version goes just a little below the flame. My logic was to get it to fit in my pot, so maybe I lucked out and also made it so canister doesn't get hot.
Second picture - very similar to first, except there are channels rather than holes at the top for the exhaust to exit. Main thing is the exhaust goes up the side of the pot, I think. Also, some heat probably gets into the aluminum and then gets transmitted to the pot (heat exchanger). But the heat exchanger part of the design is less important. Again, bottom of the windscreen/heat exchanger (whatever you want to call it) just barely goes below the flame. The port that air goes into to mix with butane is actually below the windscreen/heat exchanger.
I've been using this on a number of trips and I now use a little less than 1/4 ounce of butane to heat pint of water, before I used a little more than 1/4 ounce. What's important is that I usually heat 16 pints per trip, so I can now reliably use a 4 ounce canister rather than a little more than half an 8 ounce canister.