The thing is ...Bo is dead. DEAD. That is what Peter Reckell (Bo) wanted, and the only reason he came back to the show. So, I doubt the show would try another doppleganger story, and it certainly would not be the same to have Peter Reckell play another character........the biggest thing is......he doesn't want to. He truly just does not want to, and he is being as polite and nice as he can in saying so. We all really do not know what goes on in his private life, or behind the scenes on the show.
Back on GL, Vincent Irrizarry (Deimos) played Lujack, a character the audience loved. Lujack eventually died. I am guessing a change in writers occurred perhaps, but a couple years later, a female character went to NY, and bumped into Nick Henry, who looked exactly like Lujack. So......this story got invented that when the mother gave birth, she was out of it, had twins, the father needed $$$$, so sold one to this childless couple, never telling the wife. He admits this when Nick Henry comes to town. It was all far fetched, but Nick Henry never got the same reception by viewers that Lujack did.
And I do not think a story like that would go over for Peter Reckell/Bo replacement. It is a shame Corday doesn't pay more attention to his show, the audience, and what is going on, but he just doesn't have the feel for the genre that his parents did.