Not subtle? it is literally the episode title. Agree, this one is about choosing to ditch Saul and be James again.
And the other part is enabling both him and Kim to start to get over what happened with Lalo and Howard, something neither was able to do, without the other.
Kim left it all, the law, the place, Jimmy and Saul. But even with a new eventless routine life it is clear she still carried it. Saul went the other way, buried it by getting deeper and deeper into his alter-character. Even as Gene he defaulted to Saul, it didn't work for him. As Saul he pulls off a reduced sentence, right up until the point he learns Kim confessed. She made the first move. She is trying to move on. It still isn't enough for her though, not while Saul is still out there. And he knows it. She has taken responsibility for her part, but needs him to do the same for his.
A weight is lifted, but she still isn't back, she still isn't a lawyer, still lives away without much expression. That is why he has her attend, partly to get his redemption with her, but partly to give her hers. And you see it at the end, she has taken it, her smile is back, she is practicing law again, and discussing it with Jimmy. He has finally accepted responsibility.
The three Dickens ghosts I think are the real clever bit in this. He asks two the same question. And gives both a clearly fake different answer, a bit like the joker scars question. It is obvious he has one regret and one point in time in mind, but is not ready to admit it. The third shows us that moment I think. The question isn't asked, nor answered in the chuck flashback. But the two scenes before, and the timetravel reference with the book, suggest this is the moment he would travel to and change. He refuses to talk it out with his brother, which ultimately leads to it all falling apart, leading him to becoming Saul.
Similarly, the finger pistol gun salute he gives Kim at the end us not a token one imo. That is Her moment of regret to travel back to. That was the move she made when she went a bit crazy in the hotel room and came up with the Howard plan. The point she dived in and became as involved, if not more than he did. He does tell her at the time, there is no coming back from this. It is a nice reference and reminder that they both have to live with that.