Thanks for the review. This is a great flashlight as-is; it’s also inexpensive ($10-15) and easy to mod.
I upgraded one with a 17mm FET driver, 16mm XPL2 and spring bypass for ~1,800 lumen on a fresh 14500 (windyfire or e-fest).
My only 2 complaints were the extremely tight retaining ring on the tail (couldn’t be removed) and the lack of lube on the threads and o-rings.
I used a little vegetable oil on the o-rings to keep them from rubbing and binding up and it’s now one of my favorite flashlights.
I call it the “noisy cricket”.