First Grow - Jumping into the Deep End

This was the first full week on a 12/12 light schedule and the plants are healthy and growing well. Bucket changes yesterday for the Kushs; Kini got bumped up to 70% (1150ppm) and Lorraine is up to 65% (1050ppm). They are drinking 2-3 liters a day and gobbling up the nutes. They are starting to stretch and get bigger, but they are SO BUSHY! I keep trying to open up the middle of the plants but LST is not enough. Every time I try to shape the plants, I end up taking 5-10 leaves. Mostly the leaves covering up bud sites, or leaves growing toward the middle of the plant. However, the next day you cannot even tell. I was planning to wait to do a heavy defoliation at day# 21 of flower. However, they are so bushy I feel I need to clean them up now. It has been 10 days since flipping to 12/12 light schedule, 12 days since the last major defoliation, and they recovered phenomenally. However, I have also read that you should not defoliate between weeks 1-3 of flower, because you do not want to stunt the growth during the stretch. So, please take a look at these plants and let me know how you would proceed. a. Just LST with no defoliation at all until day# 21. b. Keep LSTing, and only take any leaves needed to expose bud sites. Wait for day# 21 to heavy defoliate. c. Defoliate now. Get rid of the large fan leaves at the bottom for airflow, and any leaves growing toward the middle. May need to defoliate again at day# 21. Anyone willing to weigh in? Will defoliating now stunt the growth? Will selecting defoliation cause too much stress to the plant? All opinions and suggestions are welcome. Thanks for reading.