I saw with great interest your approach to pruning and defoliation. I wanted to share some techniques I learned long ago, with the hope of seeing how my old approach and the new might work together?
First, I ran only one 1000w HPS bulb in flower at the time, over 12 smaller plants. The Hydrofarm open double parabola style hood was on a rotator of my own design- surprise- and the bulb ran in a circle about 15" above the tops of my plants. I mention this because I feel that one is never sure which environmental factors might be in play to get a given set of results...
To start with, when my rooted clones were about 6" tall, I topped them, and cleaned off the scraggly stuff leftover from the cloning process at the bottom. I left four and only four side buds to grow. As these grew, I often topped the highest one of these as it would try to take over the apical position. I wanted even growth on all four side stems.
Once they got to be about 6" long, I used twine and tied them down more or less horizontally, using open loops so that I could easily reposition the tiedowns later. I used duct tape to tape the twine to the sides of the soil buckets I was using, 5 gallon nursery cans.
After a week or two, I would then top each of these four branches, as well as cleaning up the minor inner buds near the mainstem. The aim was to provide two to four budding/growing sites on each of these four side stems.
Another week or two later, I would reposition the twine loops so as to keep the plant growing more outwards than upwards. The aim was to create a plant about 15-18" tall from the soil surface, and about 2 feet across at this point.
The final prune before- or just after- going into flower was to top the excessively growing shoots wherever they may have been, and to reposition the twine loops to level the canopy of the plant. At this point they'd be roughly 3' in diameter and no taller than last time, owing to the twine physically holding them down and open. I think the technique here really helped get light throughout the plant by forcing it open and keeping it that way.
Concurrently with the topping and training schedule, I'd remove lower fan leaves and assorted scraggly stuff, as it was being shaded by the upper story getting very lush and completely filling in. Once finished and looking at the plant from the side, you'd see bare stem at the bottom near the soil splitting into four, then splitting again into more branches before heading up into a dense canopy. This canopy was never more than a foot deep from bottom to top, but was very broad, almost saucer shaped. The things looked a lot like bonsai trees!
In this way, I was able to encourage consistent results from each plant, with between 16 and 32 cola sites, and no popcorn underneath which never added anything to weight anyway. All the plants were the same height as were the colas- carefully managed with the twine loops- the goal of which was to manage the vertical distance between the plants and the HPS bulb constantly rotating above.
There were always 12 plants under the rotator, six in early flower weeks 1-3, and six in late bloom, weeks 4-6. The plants were a variety I'm not sure of anymore, and I always finished in 6 weeks. They may well have done better if they'd stayed in a few extra weeks, I'll never know. Each plant averaged 4 ounces of dried finished smokable product of very high quality, since it was basically all colas. A few stars showed the way to higher potential, with up to 8 ounces on one plant...
To do this, I used a staging system like a perpetual grow; a clone zone and rooted cutting area sharing a 4 foot shoplight, an early veg under 2 more shoplights, 2 stages of peak veg under 4 more shoplights, and finally a prebloom under a stationary 400w MH, all before going under the rotating 1000w HPS.
I did the pruning I did to maximize the light I was using to flower a smaller number of plants. The bloom zone with all 12 plants was about 7 feet across. I didn't know any better at the time, so by the time I got busted- yes, snitched out- the HPS bulb was 4 years old! And yet, the yields were still up there. I never had any trouble with plant disease attacking where I'd topped the plants, and I certainly never had trouble with plants being unable to hold up their heavy buds, quite the contrary! The girls all acted like little weightlifters, constantly pulling the twine loops out of their duct tape on the sides of the buckets, even when double looped!
All this was 20 years ago; the lead officer testified in court that it ws hands down the most sophisticated grow operation he'd ever seen, clearly trying to get me some prison time. I had to think fast to counter with the fact that I was growing in dirt with cobbled together homebuilt bicycle parts! This being Colorado and a first offense, I got lucky with no jail time, just probation and fines.
I still think about that old setup every day, because if it worked so damned well then- 24-30 oz of finished product every 3 weeks like clockwork under a tired old bulb- then there has to be something of value in today's admittedly much more high tech world...