Prologue aside, The Broken Crown takes place ~16 years after the author‘s third House War book. As it was written over a decade earlier, jumping from that novel to this one results in a few continuity-related oddities where Jewel’s past is concerned.
Which ends up not much of an issue at all since very little of the story is told from her point of view. Instead it’s set in the southern lands, focusing on a rotating cast of characters each with different goals. Aside from that lack of protagonist what makes this book stand out is a persistent aura of dread; both the first and last third are thick with the suspicion that everything is about to go wrong for the characters who have managed to find some semblance of happiness. And it does, yet when the implied events finally occur they somehow end up feeling… mundane?
The Uncrowned King on the other hand is set in the Empire and has Jewel as one of the main point of view characters. It’s much closer in structure and mood to those early House War entries than Broken Crown, which makes the backstory differences a bit more jarring (it also makes it easier to read for extended periods). The only real complaint I have is how it ends up treating Kiriel. Her heritage, power, and struggle against that heritage are everything that makes her interesting, everything that sets her apart from the other characters. Why would you go and throw all that away to deus ex machina her into a (mostly) powerless human?