sun leaves fan leaves.....same thing, no difference. You can cut off some of the lower fans to open up the bushyness and air flow, but leave fan leaves that are close to the top of the plant. You still need fan leaves to absorb and utilize light.
do not cut off the fan leaves.. idk the dif between sun leaves and fan leaves. i am assuming they are the same. fan leaves act as solar panels, energy and sugar storehouses etc.. if you cut off the fan leaves, your yield will suffer.. not sure what your climate in there is but the not so perky leaves wont have anything to do with the lower leaves.. hope this helps some