My current setup is two alienware AW3423DWF monitors (plus a 3rd acer 1440p monitor to the side)
I've seen no problems with them at all, truly black blacks and color reproduction seems great to my eyes (I'm not a professional though)
HDR also works if I'm using steamdeck session on nobara, though in that case only one monitor is being used.
Here's a pic of the setup for an idea of what it looks like.
I'm using it, it still annoys me that I have to, though.
Also a premium subscriber, and I it's definitely worth it to me (especially since it comes with music and I've got the grandfathered price)
The biggest problem I have with it isn't even a problem with premium. It's that it doesn't deal with sponsor spots in videos.
Can't plug an HDMI in directly, but if you already have a USB-C dongle it should work just fine.
No dock, but you can buy one seperately (or a dongle)
https://collider.com/futurama-reboot-returning-cast-release-episodes/
Surprised you haven't heard about them.