IMHO, it becomes much more difficult to trim the leaves off when they are dry, so if you have big volume that can be a sizable task.The best dry is done with NOTHING taken off the plant. NO fan leaves Nothing. Cut at the stock and hang her up in a cold cold room. Should take 3-4 weeks to dry and will come out FIRE!
I beielve if you cut anything off before hand it will call for a uneven dry and it will probably need a jaring.
My theory is that drying the weed is something like cooking.IMHO, it becomes much more difficult to trim the leaves off when they are dry, so if you have big volume that can be a sizable task.
Also find the leaves can draw the good sticky from the bud, but I guess not an issue if you make hash/oil out of the leaves
Humidity is my concern, I will clip all the leaves before chopping if the humidity is high, as there is a higher risk of mold with the leaves on