tvOS keyboard support

[Jiandi]

What’s the expected state of keyboard support on tvOS?

I installed the Apple tvOS Steam Link app version 1.1.75 on an Apple TV 4k running tvOS 14.4.

I have an Apple Magic Keyboard paired with this TV via Bluetooth. I can use the keyboard to control the tvOS interface and enter search text in other third-party apps on the tv. I have also paired a PS4 controller to the tv which similarly works fine for controlling the tvOS and other installed apps.

Connecting the Steam Link app to the PC submitting this issue the PS4 controller works well but I've never been able to get Steam Link to accept keyboard input, either in the Steam UI (e.g. searching my library) or within streaming games.
Additionally holding the PS4 controller "share" button to bring up the Steam overlay and virtual keyboard seems to freeze the Steam Link UI. I can't find any way to select virtual keyboard keys or to dismiss the overlay.

Am I missing something? Is a similar confit working for anyone else? No combination of restarting systems and repairing input devices has allowed me to enter text via the tv keyboard.