If you have a theater nearby that offers Dolby Vision films you can try out a version of HDR. They use laser projectors so the blacks can really be pure black. When the screen goes dark just before the movie the entire theater will be pitch black except for emergency lighting. It’s glorious.
Seriously. I hate when people assume default settings are the only option. You don’t even need a Plex account to set up Plex. It will just be less seamless and user friendly. Never adopt the server, configure these via localhost (ssh tunnel works) and then set up your networking. Don’t even need to update it, it will run for as long as the database stays stable. Which should be years or more.