I made my own long Fate post rather than posting here. But to address an earlier point, spending Fate Points before the roll doesn’t break anything, and turns things into more of a gamble (that’s how it works in Age of Arthur, for that reason, to make conflicts more uncertain). And the GM spends any of their Fate points first to set a stake and call it out.

It’s a small distance from the default way of doing things in Fate Core, but it works well as my way of doing things!