I have a really cheap old as the hills desktop with an ancient Quadro gpu in it connected via a decently expensive but also used 10gb Nic to my nas which is running Proxmox and a bunch of containers, but the two interesting ones are a tailscale exit node and Jellyfin. The Jellyfin gets the gpu via pass through, and I get 1080p on tap anywhere in my house with no fuss no muss, and I can use the tailscale app, connect, and act like I’m in my house from anywhere else, including other continents. Noticeable delay on play and pause on media if I’m on the other side of the planet, but that’s it for limitations.

I’ve had a bit of success with HDMI out to a splitter that does something funky with the edid, then into a capture card. The PC detects the capture card as a second display, drag the content into it, screen cap the “second display”. I had all the gear for unrelated projects, but I haven’t found any content I couldn’t grab this way.