I'm quoting this here because it's a b o u t t h i s, thank you, yes, there's a few PODs but I did my homework and really they can all arguably come back to Cummings being ousted. The no Cummings > No Gove > No Boris > No Leave theory is a real one that IRL people have put about. Leave.EU haven't actually done much more here than they did IOTL, they were just official and still dreadful. Cameron is described ITTL as going hell for leather to win, but at least in my head he literally did nothing extra apart from the passport bit compared to OTL - it's just ITTL he's seen as having fought harder because he, er, won.
You're right that Leave wasn't per se a perfect storm but it was a convergence of lots of things that we going to boil over at some point. This is an attempt to craft an imperfect storm that still gets us out of that hole.
I disagree about Cameron doing nothing extra. Insisting that ministers resign if they campaign for Leave rather than being allowed to stay in post is a huge difference. I'm not honestly sure he would have done that unless perhaps he felt it was the only way to win. You might know something I don't though.
Interesting to read about it going the other way and how, up to this point at least, it is not that different to OTL, though what differences there are are undeniably significant.