I never did understand HDS's excessive price, considering it's very conservative with its output. Maybe it has something to do with the fact it runs on CR123, and so can't drive as much current as if it was running on 2xAA Eneloops? I think CR123 specs at something like 1.5 amps max? Whereas Eneloops can go at 5 or 6 amps. Albeit 2xAA has slightly less voltage than 1xCR123, but more than makes up for it from current.
For an example from Zebralight, the SC32 has a lower max output than the SC5, because the SC32 can't drive its CR123 as hard as the SC5 can drive an Eneloop.
I don't think under-driving lights has much to do with protecting the LED. LEDs can handle quite high temperatures, and step-down or PID can deal with excessive temps. It might have something to do with protecting the driver electronics, but I'm skeptical.
Perhaps the SC32 is capped for heat as well (less thermal mass than the 5?), no reason it couldn't shoot for the moon with an IMR 16340, it's designed for them. HDS is also designed for Li-ions, and is modular (2xNiMh and a 18650 tubes), so it could certainly do what so many lights already do - offer different max outputs depending upon cell chem/config... but Henry doesn't.
Malkoff, McGizmo, Surefire, Elzetta, etc. also under drive their lights relative to the Chinese manufacturers.... why? ZL produces the brightest lights for a given size and battery chemistry, yet has the shortest warranty in the industry... any correlation? IDK... just connecting the dots.
I really don't think there's rocket science behind extracting every last ma of current out of a particular battery chemistry to produce every last lumen from a CREE product - it's a business decision. Aside from the reliability/durability/CS reason we've been discussing, I think there are other important reasons behind it:
- By my light box, 325 lumens from a quality American Co is ~425+ ZL, AT, TN lms.
- Some don't believe in step-downs
- Some believe in an hour at max
- Some cater to non-flashaholic markets and know their customers are only going to use primaries, incl Alks (like the OP btw), and don't want them to get pissed when their light fails to achieve full output, and/or fresh cells die in minutes.
- Some find chasing the "brightest output" game futile and subject to the laws of dismissing returns - ie, due to the logarithmic light perception thing, you'll need 4x the power (or get 1/4 the runtime) to appear twice as bright.
IMHO, YMMV and all...