Now industry standard with most brands is to report lumens numbers at the emitter, not Out The Front.
For the record, that is not true (EDIT)
of ANY of the brands I buy or have bought in many years. Eagtac specifies an 'LED' number, but only right next to the FL1 OTF spec. I have no published 'LED' output number for any other lights I own (that I can think of). There's no such thing as an FL1-compliant 'LED' output spec for a flashlight.
I'm quite certain there are still manufacturers out there who use that as their published spec, and who also do all manner of other unscrupulous things I won't detail here, but they don't even exist to me or appear on my radar screen.
What lights are you buying (or referring to) that publish 'LED' output as their output spec? I'm curious (and want to know whose lights to avoid).