In a very real way, the Frontier of this universe is more like the Gilded Age of Appalachia than it is the Wild West. The Shine Corporation has a pretty decent lock down on society so it wasn't particularly "wild" with the majority of towns dominated by the company's mercenaries and their abuses. All of that came to an end with the previous book where the company's owner was taken down and his vast wealth passed into the hands of his son, Arlen.
Unfortunately, Arlen is psychologically unfit to be the leader of a massive corporate empire built on the backs of an exploited proletariat. Even if the people want him to be a leader since the absence of the Shine Corporation's rule, the even-worse Union are ready to annex the territory for its own use. Arlen just wants to treat his PTSD-ridden sister, Cassandra, and give up the Shine Corporation to the people even though no one can manage it. Really, it's fascinating as a deconstruction of the millionaire who gives away their fortune because it's clear that is just passing the buck versus improving the lives of the people directly.
The book also adds the perspective of new character Grace and former villain Elroy. Grace is a former prostitute who was sold to the Shine Corporation's bordellos when she was a girl by her stepfather (I really wanted to see that confrontation but it's sadly not in the book). Now a single mother living in a boomtown, she's terrified that the collapse of the Shine Corporation will lead to a return of human trafficking as well as general chaos. Elroy is someone that Arlen desperately wants to save despite the fact that the former is suicidal with guilt over his actions as a Shine agent.
Unfortunately, I will say that the book's biggest weakness is probably the Elroy plot. I'm a big fan of redemption stories but I also note that a lot of preclude the idea of justice. Elroy is guilty of atrocities and really should be punished for his actions. Arlen desperately tries to insist to both his sister, who Elroy murdered the adoptive family of, that Elroy was just a weapon but last time I checked, "Just following orders" wasn't a valid defense. I couldn't get into Elroy and Arlen's romance as a result as I was pretty sure he did deserve the rope and his self-hatred was fully justified.
This is a character-heavy sequel and if you aren't heavily invested in the characters of the original book, then it is not going to be great. Also, you need to remember facts like Shine allows you to see ghosts if you're completely wasted on it. Still, I absolutely loved the first book and I was heavily invested in these characters. Sarah Chorn also makes LGBT issues front and center in this story in a way that is both a major part of the characters' identities properly explored as part of the worldbuilding versus simply thrown in.
As such, I recommend Glass Rhapsody as a very different kind of fantasy. There's very little action that happens and, indeed, the protagonists are aggressively non-violent to the point the best thing they could do is impossible because they don't want to hurt anyone. That and the unique world Sarah Chorn has created makes this a solid and entertaining book. I will definitely be picking up the third installment.