The monitor in question comes factory calibrated with AdobeRGB and sRGB profiles, which are user selectable. After initially running a calibration the difference between 'calibrated' result and factory calibrated profile was minimal, hence why I stuck with the factory one. I never had any issues till now. It doesn't matter whether the monitor is calibrated or not if ACR can't read the custom created calibrated profile.
I still don't buy this "known issue with saturation". These support people usually just read from scripts, but mainly I don't buy it because it doesn't make any sense.
This is apparently a wide gamut monitor. You need to get a calibrator. This is essential with wide gamut monitors, and they simply shouldn't be sold without one. Wide gamut changes the rules completely.
There is no such thing as a "factory calibrated" monitor. This is just marketing nonsense along with all the rest. The profile is generic, but more importantly - the instant you change any settings in the monitor, the profile is invalidated and you need to make a new one. The profile needs to describe the unit's actual, current response, not some "ideal" response. This is important!
Whenever you change profile to one that describes a different monitor response - those two go hand in hand - you also need to relaunch ACR/Photoshop/Lightroom. They load the profile at startup and continue to use that profile until relaunch.
In addition, manufacturer profiles are very often not correctly written to icc spec - in other words they are defective. So the description is incorrect, and the apps display incorrectly. This happens so often one wonders why they even bother. A defective profile frequently affects applications in different ways. Dell is notorious for this, but BenQ, Samsung, LG, Acer and Asus aren't far behind.
In short - when you buy a wide gamut monitor, a calibrator is part of the package. Without one, you'll keep getting into trouble.