Why defoliate at all?
If the plants would not need those leaves, it would not have grown them in the first place!
Just remember.........
Maximum amount of healthy green leaves = maximum amount of energy production = maximum amount of growth.
Defoliation if absolutely needed for whatever reason should not be done just after switching to 12/12 or in the first few weeks of flower, these are the times when stress can play havoc with your plants........but why defoliate at all, "just because"?
Go easy on the feding too, they are very, very green.
Too much nitrogen in flower will cause excess leaf growth at the expense of flower growth.