"You can prune leaves where ever you want." Up to a point.
Fan leaves help the plant turn light into a form of energy the plant can use. The earlier in a grow the more
important the fan leaves are. You can trim a few with no problems, but, if you pass a critical point your leaves
will start to grow out white. Albino white. I had to throw out 4 plants worth of bud because I over-trimmed the
fan leaves and didn't know enough to recognize that white leaves are fatal.
Get in the habit of ignoring individual leaves. You can go crazy playing "what-if" with Mother Nature.
Good luck, BigSteve.