Here’s a bit more information from interviewing the developer, Megan Zimmerman.
Q: Is it possible to get the SteamVR assets in the Unity app to work with another headset?
A: For this solution, since I was working with the Vive, I included the prefab that works with the Vive. SteamVR works with Oculus as well. There is a little bit of external setup to enable unknown sources for the Oculus. Additionally, you could use the Oculus utilities for Unity (at this link https://developer3.oculus.com/downloads/) instead of SteamVR.
Q: Do you have advice for people streaming from HDMI? What’s your setup?
A: I have used both, currently I am using the HDMI output with a Feelworld HDMI to USB 3.0 Capture card which works great.
Q: Do you intend to put your project up on GitHub or other public repo?
A: I plan to publish it through GitHub. I’m in the process of filling out some paperwork that the government agency I work for requires. I’ll let the community know when it goes up.