People will often times point exit pupil out as the sole culprit for better/worse low light performance. It is a factor, but by no means the only factor. Just like when people try to peg "Horsepower" as the sole factor that goes into making a car fast - it's simply because it's difficult to truly understand everything that goes into making an optic perform great in low light or a car go fast unless you're basically the engineer that actually designed it from the ground up. Optical systems are complicated - Case and point would be to take two scopes with the exact same mag range and objective size, but one that costs $200 and one that costs $1200 or even more and put them up against one another. Exit pupil will be the same - is their low light performance the same when they're on equal magnifications? Absolutely not. Right there explains how much more goes into the equation. Chemical makeup of each lens in the system (Of which there may very likely be more than 10), curvature of each lens, spacing, alignment, coatings, etc. Not to mention the most difficult part of all in an optical system - the human eye and brain. At the end of the optical train, a riflescope relies on your eye to do the last focus of the image down onto the retina and the retina to relay properly to the brain what it has received and the brain to comprehend it. Brains don't always follow perfect math or theoretical "Better's and worst's"...

Anyway - to your point - the small objective lens diameter of LPVO's shouldn't be a reason to shy away from them when it comes to low light usage. If one were looking solely at optics that are comparable in overall quality and have at least mostly similar magnification ranges but perhaps different in objective lens diameter, then you would likely see better performance out of the scope with the larger objective lens. (This is also speaking within the same brand - price really can't accurately be used as an accurate quality comparison across brands because each brand has its own price structure and product development tactics/tricks/methods/etc). If you're looking at a Razor, though, like pictured, compared to a scope that's half the price or even less, and they have at least similar mag ranges but the significantly less expensive one has a bigger objective bell... Well... In most cases that Razor is likely to have the edge just because it has such a dang good optical system.

Sent your question on down to the instructors here at our range facility and they said this - "Yep - we do this with vis lasers that are slaved to IR lasers to get close and then confirm under NODS. He is saying, I believe, that by adjusting the diopter of the 1-6 you can use your NODS to look through the scope to co-witness your IR laser. Definitely doable, I've done this to look through a razor with helmet mounted NODS but never done it to zero a laser.

It would give you a converging zero at whatever distance your optic is zeroed at though it's always good to confirm. We are fans of converging zeroes."