You need look closer even closer.
Ok nitecore formulation is not clear, is not with no regulation otherwise the lamp would catch fire, it’s a theorical calcul based on a mode where the thermal regulation need not to be used.
Runtime with all other spec must be use with caution.
I take P20iX data table for explain.
Higher output 2 hour —-> high output 2h30, gap is not realistic for output x 2 power lumens more so 2h on higher is with turbo regulation and drop at high
But if you see
High 2h30 ——> mid 7h15, gap is realistic, you can conclude high (850 lumens) is approx the real output can do this light with termal régulation.
So 2h is the max runtime possible with max output possible (around 850 lumens) sustains and constant, with start higher but not sustainable output.
So with the MH12S and the Fenix on her data table, the real runtime and her real sustainable output confirmed by Freeme with the screen of zeroair test
Nitecore can sustains 1000 lumens and Fenix 700 and you can also see nitecore have more runtime at 1000 lumens(3h15) between Fenix at 600 lumens(2h35) and this is a near totally real runtime.
And it’s totally consistent with the difference cells capacity 