Anyone have any insight on defoiling fan leaves/le...

Do it after day 21 of flower or you might stunt the stretch phase. The idea is to expose leaves that are connected to lower buds that are otherwise shaded by upper leaves. Some strains don't need to be defoliated, and some others have elaves right on top of each other, which promotes high humidity, which is something to be avoided. If you've never done it, don't over do it, you can always pluck some leaves at a later day. If you look down on the plant from the very top, a defoliated plant should have enough foliage that you still see green, so the light won't just reach the soil