yeah I feel like that's a good place to stop!
It gets very weird (while still compelling) after that - I think it would get much harder to film and a lot of the things that happen are horrendous! There's a certain realm of fantasy that's very hard to actually film, I think.
Books 3 and 4 are IIRC full of backstabbing and confusing intrigues written as if they are obvious, but they really aren't. And the body horror of the "god emperor" and the Duncans.
