I use fan leaves quite a bit. I also use sugar trim quite a bit. I get both from my grower and usually get a lot at harvest. I have a fan leaf guide on another site but it sounds like I need to post it here, too, to educate a few people on getting the most from your crop. If you're getting fan leaf then in this day and age it is highly likely that it came from modern strains which are high in THC. These leaves, at least by harvest time, have quite a bit of thc in them and if concentrated enough it can produce butt-kicking edibles.
The leaves taken off early won't have much, but some. I use all of what I take off my plants. You'll have a lot more chlorophyll from the fan leaves than sugar leaf, unless they've been allowed to yellow after flushing before harvest. I make a Green Dragon extraction and then use that to make my butter or oil for recipes. Out of an ounce of fan leaves, I get about 6 fluid ounces of concentrated Green Dragon and 12oz out of sugar trim or bud. I get a minimum 20 servings of potent edibles with each fluid ounce.