Spoilers ahead, along with way too much text.
Overall, I did like all of the characters, with less space to throw them into walls and off rooves than LD they'll not have as much to them, and I think that's like most obvious with Penelope. A few days sitting with it, and I find that a lot of the contrast that she serves and plays with of being the 'normal' one ends up being played by Faye more, she's very much more involved but that is mostly in other characters scene with her not really having many for herself. Fabiane on the other hand I think has to have less characterization, to like make a thesis I think that a large part of DDDD is about how while you can only see things from your own view, it isn't the only one exists, and you can't let that dominate how you think and interact with people.
Fabiane then as someone who is given less time is characterized in ways that make her easy to write off, and thus the conclusion with Odessa killing her is heavily dealing with the fact that Odessa is functionally a fascist, killing someone for being 'undesirable' without concern for the people most affected by it or how similar her friends are to her. For setting and such, I think that the focus on a larger idea of what society is and how the various faggots interact with it is the main strength it has over Loner Dog. We see how people are able to interact with it, and crucially how like the Shelters don't just mean that someone is openly an outcast, but rather the ways that people understand the system and different roles in it. Better look into what the shelter actually is, very much acts as the key here, where it's not just like sex trafficking and other forms of human trafficking, but also the exploitation of bodies people find as undesirable. Odessa acting as the person who takes people away from the shelter is as integral to her as Fabiane's murderer as is her being Faye's homewrecker because she becomes a connection to the shelter, but also someone that I don't think ever sees what it's like in there. She's both the bridge between a shelter and a freed dog, as well as the trans and cis lives for a lot of people, meshing in ways that Roxy and others don't.
As for Roxy, I think she works as a stabilizing force, someone who creates the normalcy everyone else lives in, and while that is an important role to understanding community beyond something to 'protect', it also makes it so the story at times feels like it's teeth have been ground down some to me. She's like, a drinker, but way more casual and chill about it than Audrey who served a similar role, and crucially people seem to respect her more. I think it's like a good role to have, but I did find her kind of boring for it. Vale and Katrina ended up working really well as like, not really foils but two sides of the coin. They act as people who describe abandonment from support networks than those escaped from shelters, and I think that's a really fucking important thing to have. Especially Vale's struggles to articulate her struggles to people who are so familiar with them they are practically mundane to her. Se adds a much needed edge to the story IMO, especially when we see how Katrina went through the same thing. Mia and Lee I think are in this really weird role were they're like, not a part of the main group, but also as much of like the dynamics of how things get argued. Which, important role, I love them there, important for their not being one form of transness, and also I think the one's that really made the characterization of other characters feel shallower than they were due to how much focus is on their specific idiocintricies. While they're a highlight, it sometimes felt strange how they were given focus despite their separation.
Finally, Odessa is my favourite character. She's certainly not a good person, but I do like the way that she's willing to be more upfront about her thoughts on Faye's marriage. She's very focused on her view, what she is supposed to do, her role in things, and when someone complicates this she becomes opposed to that. Fabiane being murdered then is.... I don't think it's like purely because of fascist beliefs on Odessa's part but rather how her beliefs and focus lead to actions in line with the goal of fascism. Fabiane is hurting people close to her, and is someone easy to be disposed of, vulnerable. So Odessa kills her, because it's convenient, and because 'solves' her problem in the same way Faye getting a divorce would. At the same time, she is unable to help Faye through it, because the framing of it as a cis vs trans relationship leaves her with little input.
On this, I think the description of fascism as external fascism coming home fails to materialize, it is an internal fascism which influences how Odessa is cast out, and how Dovetail is reduced to someone who commits suicide. It's construction of what it means to be queer in a nation that hates you is one in which that hate is largely internal to the country creating the creations you live in, and in so doing Odessa's prophecy (thinking more on it, I think this is more what it's about) is more and indication that she doesn't see what's already lurking under the surface in the same way, she sees how everyone might have died in another world. She isn't special in this, despite her thinking she is, she's just another person in the imperial interior trying to grapple with how little control she has on the thing ruining everyone's life. It's greater specificity allows for some magical scenes in how people connect and their relations, but I almost think it should challenge the reader more, lead them to the conclusion that Fabianne should die. Not because it's better but because everyone's still just a dog.