Yes, the temperature effect has been removed. There have been two changes: previously the FSX era code would just use the rule of thumb of 1000ft per 1inMg for pressure alt. It would look up your true alt, check the diff in SL pressure vs std, and apply a diff to your true alt using that diff times the rule of thumb. The was not really a very accurate method, and obviously assumed that you right on the ISA pressure lapse rate curve, which may no longer be true with the live weather system.
The first change was that a new formula was added that is more accurate (the actual ISA pressure alt formula). Secondly, your current local ambient pressure is now used as an additional modifier, so that error from being off of the ISA curve is now also modeled. Unfortunately the pressure data does not have sufficient resolution to drive the altimeters directly, so we still back into this using the geometric altitude (which has a ton of precision), but it should be much more accurate in most cases.
However, I believe I’ve tracked down the issue with the pressure altitude simvar. Unfortunately, due to the platform being on two+ decades of legacy sim code, sometimes you encounter these issues. The pressure altitude simvar gets its altitude from a totally different spot and with copy and pasted altimeter code (which matches the old code). Also double unfortunately, the ATC uses this value and not the one from the pitot static simulation. ATC has a buffer of 250 meters before it yells at you, but with the wacky data being seen in the sim, it’s more than possible to get that big of a diff from the two formulae.
We should be able to rectify that but I need to talk to Seb on Monday about it further.
-Matt | Working Title