Okay so: I'm looking for an app like Orion (https://orion.tube/) that works on a Chromebook. Which is to say: I want to use an HDMI-to-USB-C capture card as an input and use the Chromebook's screen as a monitor for another device. Chromebooks can run Android, Linux, and Chrome, so I assume ONE of those platforms has an app that can do this. Right?
I am specifically looking for low latency wired options here; I know about e.g. Duet and various screen-casting software solutions.
I thought I could use OBS for this, but OBS Studio doesn't run in the default Linux virtual environment. I did get it working in a sense on an old Windows laptop but the latency was higher than I'd want for e.g. connecting a Switch.