After even more testing, this time with the FBW A320NX, the A320 tracks dead center on the LOC and GS, so the issue may lie with the AS CRJ.
Of course it does and, as as general suggestion when reporting any problems with a scenery, is to always check with a DEFAULT airplane first, before saying the scenery is "unaccurate" or requires "fixing".
KORD, of course, is accurate as it can be and, as a proper MSFS scenery, use the ( silly, in my opinion ) method of ILS having to be specified in Magnetic heading instead of True heading like it was for every simulator since FS9 and possibly even way before that.
Since MSFS now considers the heading to be Magnetic, a way to make it easy to have the ILS perfectly aligned to the runway, which is also suggested by Asobo when several developers inquired about this change, is to set the Magvar for the ILS to 0, and set the True heading so, the readout in the instruments will be correct, because it will add the overall Magnetic variation of the airport itself.
For example, KORD 9C runway as a perfect 90 degrees True heading, and we set the ILS to be perfect 90 degrees with a 0 Magvar. This achieves the result of having the ILS PERFECTLY aligned with the runway, as you noticed, with the instrumentation showing 93 degrees, which is the real world magnetic value, because the airport has a 3 degrees W variation.
Now, I can't possibly say which the ILS works as it should on default A320 (FBW is based on default) and not on Aerosoft. Some 3rd party airplanes use their own internal navigation database instead of relying on the default system so, the data they are using is not even coming from the scenery itself.