The problem is light penetration. 12-18" deep? maybe, upto 24" before you get to popcorn buds?
If too much in space you get overcrowded. Then, it's the top 6-8" with good nugs.
When the canopy is about 1/2 the square footage of what you want in your bloom area, that's a good time to move it or switch the light schedule, however you are set up. About a 7-10 days clip off the largest fan leaves blocking light. remove lower auxiliar growth that is too deep to grow anything of value. I err on the side of keeping some popcorn buds. It is a much better yield for bubble hash than trim :) But, too much is detrimental to your top colas. Cut anything blocking light from penetrating canopy.
Focus on that top ~24" zone, regardless of how tall you grow the plants, unless you have a bunch of side lighting too. Expect another 2 weeks of growth after that defoliation up top. It will grow back, as long as the plant is healthy. If it is showing any deficiencies like a couple pictures show, i wouldn't use this technique, though. It may not recover and grow back in time, and then it will only cause negative impacts. Maybe, just a handful of the larges leaves that clearly block multiple vertically growing branches slightly below.
Have common sense. Any thing, stringy nonsense isn't going to have time to grow thick enough to proide a good cola. when you need to create a bit of room between colas, that's the stuff to cut and improve airflow and light penetration. If it's too low in canopy, it will never have a chance to see light after 2 week -- cut it off.
if not super familiar with the plant, be conservative the first time. Try it in just one area of the canopy and see the difference. Like i said, i leave a good chunk of that stuff for bubble hash, but i don't want a big chunk of my harvest from it and stealing resources from the top colas as it develops.
I don't do extreme lollipoping, but the lower 6-8" of my plants are stripped. The reduction in leaf material will greatly improve airflow through the plant in addition to light hitting a large portion of the plant -- which it will react to in positive ways. Even remove the large ones down below that aren't even facing the light anymore. In soil, you may want to leave more of this stuff, but if you fertilize regularly, it shouldn't matter.
Airflow and light - as well as an even canopy - will cause the best buds your setup can provide. The tallest branches get the most resources. Even bending them down will help the others catch up. After ~3 weeks into bloom, they won't be growing much except for flowers. Can't do much if 1 dominates. The others will have inferior buds.