The Olight m2x ut XPL version i have serial number starts with E12 , all of the e11,s i have seen are xml2s and the f03 are xpl. The easiest mod to get it cranking is to use 2x 18350 imr cells- my measurements,
Panasonic protected 1 x ncr18650b- 1450 lux
Awt imr 1 x 18650- 1590 lux
Efest imr 2 x 18350,s- 1790 lux
Sure you wont get the runtime of the single 18650, but you can always access full lux till they are down to 3.5v. The single 18650 can only sustain max lux for one turbo run. If you look at olights specs it states all measurements taken using using 2 x cr123 cells, so if your running a protected icr cell and would like to increase output and throw by more than 20% go the 2 x 18350s.
I also have an extender, which also will increase output but i like the light small.