Definetely Astrolux FT03 SST40 and using Shockli 26650 5500mah 30A. It can sustain long run with less heat. I heard the xhp50.2 version will generate heat faster than the sst40 on turbo, thus cut the runtime.

More plus, FT03 operating in Narsilm which give ramping mode by simply click hold, easy single click on/off.