I have just read the post you link to, and Varakari’s reply a year ago. Now, a year later we need to look at his changes in axial length relative to his increase in focal distance to see if his experience confirms the hypothesis of axial shortening being the reason for myopia reversal.
I have benefitted from clinical blur adaptation for 30 years, as I did not wear correction other than for a little driving. That on its own did not improve my vision. So the improvements I have made since starting EM 15 months ago are not the result of permanent myopic defocus and blur adaptation. They are the result of challenging the myopic homeostasis by paying attention to my edge of blur, wherever that is, pushing a little past it, and trying to clear the blur. I have no way of knowing whether there has been any axial shortening in my case.
There are probably processes other than clinical blur adaptation or axial shortening that could explain the reduction in myopia. We would need more people measuring their axial length at the beginning of EM and after considerable improvements in vision to give more weight to the axial shortening hypothesis, or to falsify it. In addition, although axial lengthening seems to be the most common cause of myopia, it is not the only one.
Eyes returning to ‘normal’ after the 60 minute or longer experiments are the result of removing the myopic defocus. The normal could refer either to the natural emmetropic state of the experimental subjects or their full correction for myopia. This is only to be expected. It happens to me as well when I put on glasses for measurement purposes, or did so in the past for driving. It takes some time again before I regain the visual improvement of clinical blur adaptation. But this does not change the fact that my full correction has been considerably reduced since starting EM, so something has changed.