I dont think its the technical issue that holds Ady back on this one, he already remixed Vader voice quite considerably as well as enhancing many other sounds and audio. It definetly have nothing to do with the PT, if it ties them together by chance then thats a bonus but its not a priority. And its not a “fix” either its just an alternative, Vader responds “Obi-Wan once thought as you do” after Luke asks him to come with him. That is pretty much everything Obi-Wan does in the prequels, and its also what we learn about the past through the OT. Although Obi-Wan gives up when Vader is completely turned, the “once” moment does not refer to a week, a month, a year ago.