"A Memory Called Empire" ticks all of my boxes.
A Star Wars-inspired space opera whose narrative follows a murder-mystery plot. Our protagonist functions simultaneously as ambassador in an imperial society of Roman complexity.
I didn't feel particularly attached to the characters, but it's high-concept science fiction done right. The premise of implantable memories is very well developed in a plot that at times reads like an espionage thriller.
https://app.thestorygraph.com/reviews/db4e498c-ec43-43fb-8ce8-b175e6d8ea86?redirect=true