the only good reason to cut fan leaves is if you want to slow the growth of that part of the plant relative to others. for instance, i've cut alternating fan leaves off of the main stem to help the secondary branches catch up and create a full canopy with multiple colas (also topped the main stem). there is no basis in good horticulture to trim the leaves to "expose the bud sites". most of the light the plant absorbs is through the leaves and then sugar is transported throughout the plant to fuel growth. another reason to prune would be to cut off the lower nodes that don't receive much light to help the plant concentrate on the nodes you want to keep.