Those are good questions. I can only give you guesses at best on them though.
Lumen output of the stock M40A (I think manufacture rated at 645 lumens) can't be used as that is with an XM-L and at a lower current then what I'm talking about above. Djozz did some torture testing on what I think is the emitter you want for your application here. In that testing got estimated lumens of about 413 at 3.4 amps. It appears that the the best current would be about 2.7-2.8 amps (the 3.6 I threw out above is too high) which would yield a little less than 400 lumens. OTF would probably be maybe 10% less as a guess. The M40A has an A/R coated lens. So the lose would be less then other typical lights.
I'm not aware of any standards, but I could make the light and then tell you what the hot spot measures at a distance of your choice. You would not be obligated to buy the light as I'm curious how the combo would work out.
Are you seeking a certain level of lumens? Lots of lumens, high CRI, and narrow beam all work against each other. You could get lots of lumens if if you go multiple emitters, but you will be getting into floody beam territory. There are a few mufti-emitter lights that have narrow beams (or atleast smaller hot spots then other multi-emitter lights), but they are li-ion lights. There are just no proven small (for throw/narrow beam) emitters that have high output levels that I'm aware of (I'm not an expert in this stuff).
Are you looking for a narrow beam or are you saying in the OP that you could settle for a narrow beam? I ask a narrow beam and AA's is limiting your choices a whole bunch. Nothing wrong with that. Just wanting to make sure I understand what you're looking for.
EDIT: This emitter will get you up to about 550 lumens according to this testing. We don't know if it is truly 92 CRI though. I have some of them and really like the tint and apparent CRI. I should say that I'm not a good subjective judge of tint and CRI though. I don't think I have ideal color vision.