I got NarsilM in small 16340 lights, including with 3 channels, so it's certainly possible. There's a few options, like using the smaller 3 leg FET's like we've been doing. Could go to dual boards like in the GT Micro.
Here's the OTR M3 modded, running NarsilM: https://budgetlightforum.com/t/-/43390/10
