Guys, if you're nervous about running a light on 16340 that isn't documented for it, just contact the manufacturer. I have a Klarus XT1C, which is not documented for 16340, so I contacted Klarus, and they told me that the circuit can handle a 4.2V fine, and the reason they don't document that is for heat issues ... but if I turned the level down before it got hot, I was fine. I run the light on a 16340 now, LOVE the brightness on high, works great.
So, if you have questions, just email the manufacturer.