I think I get what you mean - in the example I mentioned what's needed is a un-tonemapped plate with a LUT preview in the rendered VFB, with the rendered CG output next to it, maybe processed with yet another LUT, this is slightly different. Yeah, probably not the best fit.
What I meant is more about how and why it's useful to have, or even a must in some productions. Sure there's some leeway in every production :D but there's a reason a display transform is part of OCIO and LUT preview was considered useful/mandatory in 3ds max some 15-20 years ago.