For reasons that still remain unclear to me, I read through this thread.
If one is going to use "butterflies" to explain a major change down the line, one doesn't get to just say: "Butterflies". That's lazy writing, and insulting to the reader. The butterfly steps have to be shown.
In my TL, The Death of Lt Arthur Windsor (which obviously wasn't that good, because it never even received a mention of a nomination, so treat my comments with as big a pinch of salt as you care to use), there were a lot of butterflies. For example, a no-confidence vote that OTL was a close victory for the Callaghan government was a close defeat. This lead to a 1976 General Election, which led to a Tory victory, and Thatcher becoming PM in 1976 rather than 1979. I tried as best I could to keep people acting in what I saw as their character, with reference to the changing situation around them.
I'm a professional writer. It's what pays the bills. It's my view that butterflies need to be explained. For example, in OTL, the 1976 Peace Marches in Northern Ireland (mostly) gained a lot of publicity, but eventually fizzled out, and the result was that the violence continued for another 20 years. Here, the different pressures resulted in something that wasn't exactly peace, but wasn't actually two sides with multiple factions blowing up Mothercare shops and back-street murders for "The Cause". I could have just announced by authorial fiat that the Peace Movement achieved something; it felt more satisfying (to me, at any rate) to show the development.
That said, the views of people who wrote TLs that actually got nominated undoubtedly carry more weight than mine.