I did an experiment with these upon harvest and I can show you the results here. When I saw amber at the very top, I determined that harvest time was upon us. I sat one plant out away from the light, but still in the 12x6 bloom room. I wanted to see if I could see an effect on a plant that was like setting it in the dark for 36 hours, by only taking it out of the bright direct light 18" away from the NextLight MEGA.
My theory is that it is simply the bright light degrading the trichomes during that last day that does not allow the trichomes to grow a bit more, like they do in the dark. So at the end of that day, I pulled the plant into the corner until the next day at that same time, 36 hours later. The trichomes on the plant in corner were in general twice as long as what we could see on the control plant. There is definitely a difference between the two plants, and even with the naked eye this difference can just be seen.
I will now have to do a test of a plant in the corner vs a plant actually in the dark to see where the best benefit can be found, but this experiment brings up some new possibilities for people without a spot that can't achieve the darkness for 36 hours... maybe just slipping a bag over the plant still in the grow room would be enough?
Here are the microscope shots. First, the plant in the bright light, continuing another normal day.
Here is the plant kept in the corner, in indirect light.