Hoppharridan
Word of honor: ADC, DADC, or regular baro altimetry is not temperature compensated for published approach altitudes. This topic got thoroughly talked over last year on this website. I was initially of your view. A number of emails later, with a training captain at a Canadian jet operator, proved otherwise. Afterward, I found the ICAO chart quoted on page CA-19 in the Canadian section of the Jeppesen materials that precede CAnadian terminal charts. I recall that the most dangerous scenario was a non precision approach at a sea level airfield near a coastal range of mountains, or a non precision approach to an airfield with an exceptionally low MDA due to the complete lack of nearby obstacles. In both cases, since you lacka glideslope, you descend to a baro altitude, and the terrain clearance from which the MDA is based, no longer applies. The numbers were I remember 1,200 feet low at minus 40 celsius if you're about 4,000 feet above the altimeter reporting station, and about 120 feet low if you're at,, say, a 400 foot MDA at that flat airfield.
Ask the Canadians. They know.