I also think that they look great! Good job!

I fall into the camp of not wanting to cause any extra stress if I can help it. The way I see the initial 24 hour darkness period going into flowering is this... its two adjustments actually... from 18/6 to darkness... and then from darkness to 12/12. I am not a fan of this method. 12/12 immediately gets the point across just fine.
At the point of harvest is another matter entirely. I can definitely see the logic in trying to get the plant to believe that the end of the world is upon it... and it is time to shed all possible oils into those buds, actually trying to send the last little bit to the seeds it may have produced in order to maintain the survival of its line... which of course is its only purpose in life. Stress here is what it is all about, the plant is dying and preparing for that end.

Emmie