Having read through through all the comments of this topic, I would like to add the following:
1: I agree that the label “QNH” is misleading, because an altimeter is not restricted to being set to QNH (QFE and QNE being two obvious examples). Another example would be to “zero” your altimeter on the runway before take-off, for circuits, or set it to airfield elevation before take-off. You could also set it to the GPS alt before take-off (potentially the most accurate ??). So, to me at least, “ALT setting” is less confusing.
2: The altimeter (pressure-driven) appears to work by comparing
. /environment/pressure-inhg (the pressure measured outside the aircraft)
with whatever
. /environment/metar/pressure/in-hg or /environment/pressure-sea-level-inhg is set to (i.e.: the sim QNH / sea-level pressure). This QNH in turn appears to derive from either what the
. Basic weather>>QNH setting is
or the
. Advanced Weather>>METAR that is chosen.
The standard choices of METAR vary between 990 (CAT I minimum) and 1028 (Core high pressure region). About a 1,000' difference? Consequently, I think it should be made clear that - if an ATC (or other pilot?) is advising a pilot of the QNH - this will only be valid if the ATC weather setting QNH is the SAME as the pilot’s. Admittedly, if all concerned are using live weather, this should not be an issue. As a side-matter, the pilot could also just look up this “personal” QNH value in the property tree (in the absence of an available ATC?).
3. I’m quite surprised that the issue of QFE appears to be considered fairly trivially. It was one of the very first issues I had to get my head round when I learnt to fly. But this was in the UK and over 40 years ago - so maybe things have changed

When you are doing circuits-n-bumps around an airfield you don’t want to be constantly doing the mental arithmetic required to figure out how high you are above the runway.