There's some significant variation from driver to driver (MCU and diode), so each light should be individually calibrated for it's voltage reading to get it precise. I don't see it in the Anduril manual here, not sure I missed it. For the most part, a 0.2V difference won't make a big difference in LVP - LVP will still work fine, just on yours it will kick in on 2.6V instead of 2.8V which is still safe for the battery.
If we used a voltage divider in the design of the driver, it would be more accurate from piece to piece but a higher parasitic drain and we lose a very valuable I/O pin.
I got a unique custom configured diode voltage drop setting per flashlight I mod with NarsilM, adjusted to 1/100th of a volt. I can get it pretty accurate by sampling with a bench PS or using a few batteries at different levels.
Calibrating temp and voltage is something I really need to get in to the NarsilM UI, or Anduril at this point. It's a pain to re-flash for these adjustments.