Was going to leave a “smart” remark, but seeing as how we’re neighbors, that didn’t seem… neighborly.
The question is, how bright do you need it to be? The S2 Baton gets you 400 - 950 lm. My EDC for years has been a Jetbeam RRT-01, and when needed it makes a good mouth light. Infinite adjustment and 600 lumens max - anything more would create too much glare. I probably don’t set it higher than 400 lm for mouth use. A light this size, using a 16340/18350, should be easier on the mouth and teeth than the S2’s 18650.
Looking at my BLF/Lumintop FW3A, the shape is good for mouth-holding, it’s not much larger than the RRT-01, it maxes at 2,800 lm, but the heat at higher settings will probably not be kind to your lips.