I found this site over a year ago (and may not be remembering the details properly) so please cut me some slack if you don't find it useful.
He has software that plugs into LR but the tips he gives may be helpful. Not sure this
exact link is what you need to have a look around. I remember a video of his that I think was on youtube or vimeo where he talks about the "holy grail" transition from day to night or vice versa and how two edit the images in groups in order to minimize the work
.
Good luck!