Tynan

I’m glad you included the April Fool’s Day link. Comefrom is the worst thing I’ve ever seen.

Scrcpy does this. If you delve deep into the options you can even set up keyboard input only, but the default is screen mirroring the tablet to the computer. As to whether or not it works before running your OS I’m not sure, because it works via ADB.

Better for mobile applications, which I realize TVs are typically not but sometimes they can be mounted onto a cart or something.