I'm pretty sure Void has run tests to see how the freeze thaw cycles affect the yield, and has found it to be negligent at best. Don't think he does it any more.

I have not been as meticulous in my testing, but didn't notice a meaningful increase, and after reading Void's results, I've stopped doing it too. Pretty time and energy consuming, and unless the increase is noticeable, I'm not sure there's a point, even if it might seem to make sense