..... I have read about this previously, tried it, and found that it does not fix or even reduce the problem.
My SP7 is on its 4th day of no freezes after turning off Panel Self Refresh and turning it off for both "On Battery" and "Plugged In".
Your three cases and other cases reported here and in other areas of the internet suggest there may be various problems with the Surface Pro products. For example, while you can sometimes bring yours back by touching its back or plugging or unplugging the charger, that never worked on mine.
This Panel Self Refresh thing was recently highlighted by someone running two monitors off their Surface Pro. While the embedded monitor froze, the second monitor did not.