I would like to see a side by side of this theory on same clones (maybe I'll run it myself) have 1 plant go into 12/12 on day 1 and another into 24 dark on day one and see if they show noticeable difference, I don't know that it would make much difference, plus I'm a patient so I'd probably get medicated and forget to turn the light back on lol.
I have chopped plants straight from garden and have done 24, 48, 72 hours of darkness prior to harvest, I have not done enough testing to determine if there is a benefit to sticking em in the dark prior to harvest.