Originally Posted by Platcomike

Sometimes the fees will go up because of the routing change. I once HAD to pay $1.25 !! (they offered to "fix" this, but I said naw, go ahead and let me pay and save you the trouble. They laughed, thanked me, and I had both of my (separate) upgrades about an hour later).

I have had friends on the same flights, and I was always upgraded sooner by having the separate segments. In one case a friend was not upgraded on either segment, while I was upgraded on both. He had the same status as me. So, always have a separate PNR for each passenger AND separate segments if you are trying to upgrade. I don't know of any material disadvantages to doing this.