All those plausible theories are just that: plausible and theories. Who knows what's going through Johnson's head right now? Who knows what will happen in the future? What good is this sort of analysis, that's based on some vague attempt to form a theory of mind of a particular person (rather than a class of person, say) by people who have never even met the person in question in, er, well, person?

In any case BoJo and all the Tories on the side of Leave are typical populists: their tactic is to agitate and profit. They shake the tree until office falls out, then make a grab for it. In chaotic times, the populist leads, so the populist actively tries to create chaos, in exactly the opposite manner than reasonable politicians do (regardless of whether they are also intelligent, capable or not).

This is BoJo's time. It's futile to hope otherwise. The whole country abandoned reason. The prime idiot is not going to back down now. Those people are not in this game to leave a good name for themselves in history: they're in it to do well in the here and now, and damn the rest of the world to hell.

If the reasonable people in the UK wish to retain control, they have to get their noses out of their consolation drinks and squeeze their brains hard to come up with actual ideas, rather than pipe dreams and wishful thinking.