Here are a couple things I cobbled together to improve the experience on desktop.

Dark mode: https://userstyles.world/style/30289

This requires Stylus or something equivalent. I primarily customized this for the homepage feed, so other sections might be the wrong color or incomplete (since I never visit those sections really). I might update it some more. I'm not a graphic designer, I basically just made the background black and adjusted some button/font colors.

Automatically remove spoilers from books in feed: This requires Greasemonkey, Tampermonkey, or Violentmonkey (tested on Violent). This is a nuclear option for spoilers. I got tired of seeing the spoiler blur on books that I already read, but are still in my feed because I want to read what other people post. Until the day that Pagebound hopefully adds this as an official option, all spoiler blurs can be removed on desktop.

https://pastebin.com/7KXs6VhY

Note that this will unspoiler all books in your feed. If you're worried about actual spoilers, either don't install this, or use the app when you're currently reading a book and/or only use desktop between reads so you don't get spoiled (I would also set "TBR books in feed" to off).