Well laziness got the better of me and I never did make the Pepsi stove.

I did however just do an outdoor test with the Triad. It's about 30 degrees (just below 0 C) and I did the same test with the exception of adding a wind screen as it's a bit breezy tonight. The water boiled in about 15 minutes though it never boiled as hard as it did inside. The stove petered out after 19 minutes.

I had no trouble lighting the stove and it primed just fine without the wind screen. With a lid on the cup, performance would have been much better.