I do think that Johnson is largely bluffing, for what it’s worth. The only scenario where it is logical for him to implode constitutional norms to force a No-Deal Brexit, is if he is such a Brexit “true believer” that he is willing to end his political career to see it done. For that would indeed be the outcome if he actually pulled any of these shenanigans. Instead, everything we know about Boris suggests his real political convictions are not very strongly fleshed out, and what is more important to him is the accumulation of power and prestige.
It makes sense to talk constitutional hardball now so that when he loses the expected VONC, he can say he did his best to try to get Brexit done. His likely hope is that in the general election that follows, he has shored up enough of the hardcore Leave crowd on his side that he can hold the Tories together and win a better working majority. Johnson polls as being quite unlikeable, but I think polling also suggests his party could indeed win a bigger working majority. Predicting British election results is an exercise fraught with peril though, and while it’s hard to imagine Corbyn-lead Labour winning any form of majority who knows at this point.
I think Johnson’s path to long term success here is very narrow, if I had to guess his game, he is hoping something happens in Parliament that delays Brexit but in a manner that paints him as having been the thwarted champion of Brexit. That would shore up his support among Leave Tories and presumably set him up, in his mind, to then win a stronger working majority at the next election. What happens in the interim is more difficult to say, if there’s something like a Benn-lead caretaker government that requests an extension to the 10/31 deadline, then Boris can avoid the “blame” for delaying Brexit, and maybe he then wins the subsequent general election.
Even then, he’s right back where Theresa May was, and I don’t see any general election result that gives him a majority vote on a Brexit plan of any sort. The fundamental issue remains there is no working Brexit plan that can sustain a parliamentary majority (especially not one the EU will agree with), and while Johnson could position himself to win an election, I don’t see how he can work out the problem any better than May could. Maybe his ultimate hope is to have a more firm working majority so he simply would avoid losing a future VONC, and thus he could just let No Deal Brexit happen when the (presumably new) deadline hits. That seems like dangerous waters, as No Deal Brexit is still quite unpopular.