Never had issues with Elara but there were issues with Quinn. I chose to side with the Republic on Iokath and so it registered that I had "rejected" him in the companion window. However I was able to obtain him via the companion terminal on Odessen. Despite this, he doesn't register as an available decoration when I scroll through the decoration window and it says I don't have him. This is different from, say, Torian, who I chose not to save at the end of KOTET but who is available for decoration regardless once I recover him from the terminal.