I'd remove a lot of the lower nodes any time now. The plant is still using energy to grow them out that could better be used growing the whole plant and bigger bud sites up top. If leaves associated with the nodes are getting light you could leave those on but take out any smaller ones that are completely covered. Just snip the little emerging nodes out with some fine-point scissors. They will eventually become side branches on the side branches if left alone and yield nothing but tiny popcorn buds.
I'll sometimes leave a few for future use as clones or for dusting with pollen to make some seeds.