(some spoilers follow) I really loved both books! (For some reason the italics didn't bother me; I hope that doesn't mean I habitually use too many italics in my own writing...). The two things that didn't work for me were what in a fanfic I would call untagged body horror (it wasn't wrong for the book, but now I know exactly what chapter I'm going to skip whenever I reread) and Nine Hibiscus' chapters. I liked her (er, italics, right), but found her so straightforward that there just wasn't as much there there as with all the other POV characters, and I wonder if it might not have been more effective to give her POV to Twenty Cicada himself, or even to her antagonist, what's her name, Sixteen Moonrise?
Like you, I love Mahit and Three Seagrass' relationship, and adored Eight Antidote (and will enjoy his chapters more on a second or third reread, now that I know he's not going to come to a horrible end) and I was fascinated by the subversive Lsel comic artists. I know some people have criticized the worldbuilding; for me regardless of the larger-scale worldbuilding issues, Teixcalaan and Lsel and surroundings feel well built in the sense of a world you could live in, with cuisines, various arts, languages and dialects, sports, different shades of beliefs, and so on, and that always does it for me. I'd like to read a series of ordinary novels, as it were, set there--nothing necessarily to do with empires or invasions or aliens or whatever, just a murder mystery or a YA novel about a sports team or a historical romance or whatever, among ordinary Teixcalaanli (whatever the plural is) or Stationers.
Sorry, I didn't mean to ramble at you!