How does ArgyllCMS cope with this, are there any plans (or even just data on the deviation) for the future? I find that not only software
Currently the instruments are assumed to provide correct XYZ values. Generally you get what you pay for in this regard. Some colorimeters don't work so well on some displays, and this is a good reason for buying a spectrometer. While it's perfectly possible to create correction matrices for particular display/colorimeter combinations, in practice there are stumbling blocks. A major one is that it's a combinatorial explosion. I don't even have access to all the displays that support in-display Luts, never mind the thousands of other LCD displays out there, so I can't supply such correction matrices. (I suspect it would be a full time job keeping up with them, even if one were suppled monitors by all the manufacturers). The other problem is that one particular instance of a colorimeter doesn't necessarily represent the average for that type of instrument. One needs access to a statistically significant number of instruments to overcome this problem. [A systematized solution would involve the display manufacturers publishing the spectral characteristics of their displays in a standard format, and having some means of measuring the spectral sensitivities of the instruments.]
developers have to face the problem of designing their software so that it uses some form of CMM, but that the profiling process itself is affected by the changes in display technology.
The profiling is not affected. Shortcuts taken by the colorimeter makers do affect their accuracy though. Graeme Gill.