Over the course of 3 books and book 4 demo, we are obviously well aware that all the members of UB are vampires. Trained, professional government(s) agent vampires, but vampires nonetheless. I would have really loved to see them BE more "vampiric" if that makes sense! They clear a lot of myths in b1 that don't apply to them, but I would've really loved so many of them to be applied. They don't feel like they are very much vampires, given how less we even see them using their physical abilities in the book other than just fights and not wanting to sit in the detective's car lol. There are no quick movements, and even the bloodlust bit that vampires are famous for only comes up a handful of times.
It would've been interesting to see them have things like "not entering a place without permission" which would make a lot of their way to navigate around missions a bit different! Silverware is very subjective from detective to detective but it would've been fun to see if they had some kind of reaction to it! I like that they have their pheromone abilities, but they even mention that they don't use it a lot anymore so it feels like a wasted potential. "Compelling" with their pheromones would've brought newer angles on how they could've navigated wayhaven as a whole.
I feel like UB's potential as Vampires is not really well utilized in the books. Even if throwing everything else out of the window, just the bloodlust itself was the main focus of the vampires of this world, their hesitation towards the detective in so many aspects would've felt at a higher stake than now. They all seem to function fine around humans and even with only the detective's blood being more appetizing, they have no problem with proximity with them unless it's like breathing the same air level of close. Ik it allows for a lot of scenes in the book to work better since they don't have such limitations, but idk, I'm mostly just yapping that it'd be kind of interesting to see.