Dual Render Fusion is the recommended path to use Snapdragon Spaces on AR devices with a companion controller. I would recommend you use it in any case.
The companion controller is communicating with the unity app via input action bindings. The reset button for example is used in our Snapdragon Spaces Samples without Dual Render Fusion. The XRControllerManager references the controller profile that you can use to access the input bindings.
Here's the menu button for example:
Are you still facing any issue?
Kida-manabu