Questions about OWC HDMI Headless Video Accelerator

Yes it also works with the m1. I use it together with the Display Menu app from the appstore to adjust the screen resolution.

The part only pretends to the system that a monitor is connected. It doesn't matter which operating system is connected. I need this because Nvidia Gamestream for streaming games to ShieldTV only works when the graphics card thinks a monitor is connected.

Erm. You're confusing OWC and Adafruit. Adafruit products are mostly designed and manufactured for Raspberry Pi's or other developer platforms, therefore cheaper.

This stick cannot do that. The OWC headless stick is intended more for servers which simulates a screen for the graphics card where there is none. Operating systems often have a resolution problem when no screen is connected. It transmits nothing at all. Your description points more to a Chromecast (Art. 5636402 or 6932684) for Android or Airplay (I don't think I have any experience with it) for Apple problems. Try it with these.