I can relate to the crowding issues. Training techniques can help but for a long time (still) i tended to cram as many 2 or 3 gallon pots as i could in, LST everything down, and barely fit like 8-10 plants wall to wall like that.
You get really good yield that way, and it's good way to have backup/redundancy as a newbie in case a plant doesnt come out right your crop is still good...
But the defoliation. Oh lord the defoliation. Especially with my 3W LEDs, got poor penetration, had to defoliate daily to get the bottom nodes some light.. otherwise they would wilt and turn to larf at best or mold-bait during finishing.
First grows are scary but exciting! Liked and followed!
Looking good; I think you will be happy with the results of the flowering.
Main thing to know is that as flowering progresses, the plant will become more and more sensitive to stress of any kind; heat/cold, water, light, etc. That being said, your temps seem good which is a really good indicator there.
Let us know if you have any other questions =)