I have experimented with heavy defoliation and I will tell you it has its place in horticulture. When you SCROG and have tightly packed colas, it has benefits that may not necessarily yield more or less, if you only have a 4x4 or 4x8 space to work with and want to maximize your canopy, thinking out all the leaves after the stretch helps with humidity inside the canopy, plants respirate 97%+ of water they uptake. When your really packing them in I believe it helps get the light deeper into the canopy and helps control the potential for mold and helps with airflow. For the old school way of thinking of not touching the fan leaves, you prolly still grow with HPS..The wave of the future is LED it’s grams per watt, it’s going to be efficiency if your going to compete. HPS is 1-1.5 grams per watt..LED is 2-3 grams per watt. All the old school HPS guys will loose. They won’t make it when the gold rush is over and the market tightens up..