Claim that LUT should
always be considered as final grading is false.
Actually, LUTs are originally meant only as a means of viewing images in correct color space from image capture devices, such as photo and video cameras. They were never originally intended as postprocessing "looks".
In Corona, LUTs are often used as postprocessing looks, but there may be for example an use case, where you have an image, which was captured with a camera that applies certain correction to it right when it's captured. Then you have that certain correction process reproduced in LUT, and you want to apply it
only to your CG objects, leaving backplate alone, so that using a LUT, you will make tones of your CG object match the tones of your backplate.
Making CoronaOutputMap ignore LUT would be equally, if not more wrong then current behavior.
Solution in this case is very simple: CoronaOutput needs to have options on which parameters it should counter. I see it as 3 checkboxes, all of them enabled by default:
Exposure is self explanatory, Tone Mapping includes everything else aside from LUT, and LUT includes, well... LUT :)
The problem here is that somewhere in the process, there was made an unwise decision that CoronaOutput would be also color correction map, so adding these controls would make purpose of the map very confusing for both beginners and users of other renderers. Solution here is to make CoronaOutput strictly a map, that counters VFB color correction, and separate other controls, such as brightness, contrast, saturation and LUT applier into separate map - "CoronaColorCorrect" map.