Anyone feel that Mukuro was the Estraneo Family's experiment to harness the eighth flame?

My thought came from the fact that Mukuro (currently) is unable to wield the eighth flame and neither was D. Spade. But when Spade possessed Mukuro's body, he was able to use the flame. The Estraneo family were cruel and wicked, but they had some "interesting" science. Maybe they were onto something here...

We know the Estraneo were wiped out, but I can't help wonder what sorts of things did they do to Mukuro. He seems to know a lot about different things. Perhaps he had a Byakuran (or Spade) moment in the future. During the future arc, he was pretty much in Vindice prison for many years. Maybe he took the time to explore the outside world and noticed some things.