Hi all - I put together a simple native Apple TV app that serves as a Roon Web Display. I put the source code out on Github here: https://github.com/MattTW/Roon-Display-tvOS. Note this isn’t a player, but a display. Roon’s Web Display feature requires a full featured browser component to work. Apple TV can do this via private API, but this means it will not be accepted to the store (that is why you have never seen a web browser-like app in the Apple TV store).
That means you must build and deploy the app yourself using Xcode. The good news is that no coding expertise is required. The bad news is that if you have never messed with Xcode or are not a programmer, it might be daunting (but doable). I have provided basic instructions in the repository.
Enjoy! Contributions welcome!