if your tric's at the top are already milky, your plant is already too mature to think that your lower buds will bulk up. basically what im trying to say is that those lower buds are already at their maximum size. if your going for weight there's not much more you can do.
if you want to harvest milky trics go ahead and cut the buds off to allow the light to get to the lower buds but this will only make them mature a little faster. cutting it might even put it into shock and slow down the maturing process.....
those are just my thoughts, stinky you got any facts for us?