[reagcz]

I still use the original steam controller, and I can tell you this is not true. If steam is not launched, the controller runs in a keyboard/mouse emulation mode and is not detected as a controller. This behavior is hardcoded in the firmware and cannot be changed.

[Orygin]

It's not hardcoded, you can configure the default profile for when Steam is not running, and you can set it up as a gamepad