I'm not saying the Luthor-Clark clonebaby thing is a bad thing, it's just that it was a sudden retcon for the purposes of giving Kon something to angst about. He didn't like being a clone of Westfield, but he didn't get into constant angst and Cloning Blues about it. Hell, he would constantly crack jokes about being a clone. As for being a sudden retcon, are we to believe that in all his time working with Cadmus and various superhero organizations, they never did a blood or DNA test?
Now that Kon's alive again, I kind of want him to claim LexCorp. He's half-Luthor, and Luthor publicly recognized this, so theoretically any of Luthor's assets that were seized or suspended after he went completely supervillain would go to Kon. And it would be fun for Lana to have to work with yet another Super-kid.