With some raw files, ACR silently corrects color fringing (lateral chromatic aberration) even when ACR settings are ALL OFF. This happens with some brands and not others, as if there is a flag in the raw file that says “just do it”.
The actual lens performance for color fringing can be seen by comparing output from Iridient Developer with corrections disabled to output from ACR.
A recent example with the Sony FE 24-70mm shows this behavior in a very obvious way, but it is also a problem with the Olympus OM-D E-M1, and many other cameras. Typically, DSLR images from Canon and Nikon are unaffected (I’m unaware of any such behavior with those DSLRs).
I don’t have any contacts on the Lightroom team, and my Photoshop contact has not responded to my inquiry on this matter as yet.