Thanks for these pics; I love to see what’s inside stuff, flashlights included!
You mean human vision registering brightness in a log2(N) way, right? Yes, I’m aware of that regarding lumens; wasn’t aware it also applied to candelas, but OFC it does as AFAICS candelas is just concentrated lumens (lumens/cm2).
Thanks for the confirmation. I just went to Google and searched for the LR2170LH, and was led right back here to BLF and this post of yours: Solved: Solving the mystery of the Nealsgadgets "LR2170HP" 21700 ultra high current cells
Interesting to note that the LR2170LH is capable of supplying 50A vs 45A for the P45B (so only ~11%+) while storing only 3000mAh vs 4500mAh of power (therefore ~ 33% -); as human perception of battery duration 
is quite possibly linear, I wonder whether the added CDR is worth the lost capacity…