The Audyssey Guide over on HTS advocates raising the mic 3" for two of the eight positions (the MLP, and one position 3" in front of the MLP). I don't know how you could measure the difference between two calibrations, one with no height variations, and one with height variations, because the minor measurement differences are most likely attributable to slightly different mic positions in the horizontal plane. So, we are left with listening tests. Either it sounds better, or it doesn't, and if it sounds better, one must factor in expectation bias.
In Beast's case, he has made enough other changes that the simple mic height variation may not be contributing anything to the improved sound. The ceiling treatments surely would make a significant difference, as I found when I added them several months ago.
IMO, this thread is obsessed with minor deviations in mic placement, as if this is resulting in huge differences in the calibration results. Even for an obsessive personality like mine, I think this has gotten completely out of hand. Where is Feri when we need him?
Edit: I forgot to mention that "malarkey" is a perfect description, Keith.