suggestion for the best emiter

Hello guys, i need your help in finding a good emiter for my edc build.

so the build plan is.

1) battery - AAA/16340/10440
2) TIR OPTICS
3) 500-700 ma maximum drive ( with lower drive currents for lower power mods

so, my problem is.. i want the best possible emiter for this setup.
i can make driver with vf from 2.6-3.2v range ( with components i already have)

i am looking to build a 10-400 lumen build for keychain .

nichia 219, xpg2-r2, xte ,xpl hi v2 are some emitters i have

when i look into xpl hi, considering the lower drive current i have, its efficiency is 2.xx lm/ma, but those of xte is 3.xx and the same for xpg too.

but the problem is i didn't find many flashlights using xte . whats the problem with xte? ( i have quite few of them laying around)

i know there is better emitters which suit my need in xpg2 family. but right now.. i dont want to buy any more .. i already have a xpg2-r2 . and quite few xte's

so what are ur suggestions about these emitters? please consider the optics too.. its 25 degree tir.

and one last question.. why people prefer xpg2-r2 over xte series? efficiency? new model?

hope you guys will show me the path.

Nichia 219b 4000k gives wonderful colour rendition, like turning on the sun! Worth sacrificing a few lumens for in a small light in my opinion.

I'll second chorlton, I'd always lean towards higher CRI, even if it means lower efficiency. I'd also consider the color temp of the LED that you have to choose from--my decision might actually be more swayed by CCT most, by CRI a little, and by efficiency the least. If efficiency were the only consideration in LED choice, the light will end up with a low CRI, very cool emitter (which might fit the bill for some applications--it is all based on personal preferences and intended use).

Samsung has some good efficient 80+ cri 4000k and 5000k emitters. They also have 90+ CRI, but I think those are more difficult to obtain.