Thanks! Not a lot of sophisticated measurement tools on hand at the moment, but if I run it on turbo, I get about 1 minute until auto shutoff - might need to revisit that issue. The head is barely warm at that point. It never reaches a point where it’s unbearable enough to not hold. A proper copper heatsink might yield better performance, but I’m running into issues with getting the light to run for a couple minutes after the shutoff - probably due to the heat in the head.
I’m going to call her cheetah. Crazy performance, but only for a short burst then it needs a nap unless someone else has tips (or kiriba-ru wants to run me a custom spacer for $$ ), this will probably be the handicap with this build
Or with different words: if you have more surface area, you can get more power and don’t care if you need to take it with bare hands.
You can turn on S2+ and take it to your hands after some time, it will be comfortable if the output has not exceeded 5W.
S21 gives you 20% more.
S11 gives you 45% over S21.
unless someone else has tips (or kiriba-ru wants to run me a custom spacer for $$ 
), this will probably be the handicap with this build