Cameron, I echo your sentiments. The screenplay is not formulaic, but manages to follow the characters, primarily Ron, but also Flip, as they navigate some very tricky challenges in their undercover operation. And yet, the structure of the narrative feels quite traditional even down to the big Final Struggle / bombing scene, the conventional build to an Act Three ending. It’s another great example of how writers can work with three act structure and tell a compelling, unconventional story by leaning into the lives of the characters and — in this case — a highly unusual story conceit.
Real life doesn’t often lay out in three acts, but what the screenwriters did with BlacKkKlansman is find a solid Beginning / Middle / End structure while servicing the key characters and their respective arcs.