I don't know if you noticed that one of the use cases I mentioned was level artists. 9 times out of 10, a level artist isn't trying to optimize some specular hi

I don't know if you noticed that one of the use cases I mentioned was level artists. 9 times out of 10, a level artist isn't trying to optimize some specular highlight in a vase, they are trying to see if this room is lit in a good way (aesthetically pleasing, the player can see the right things and so on). So I agree that there are use cases for which a fast denoised preview isn't useful, like the one you mention, but there certainly are ones for which it is quite sufficient, and infinitely better than waiting around for minutes waiting for the lightmaps to bake GI.