Now you can play game with VR device using keyboard and mouse, without tracked controller.
For example, if you want to play with Oculus Go via RiftCat, The position of Oculus Go controller is not tracked. So you must want to use keyboard and mouse.
How to start
Please Play with option "Launch Virtual Hand Mode in Steam VR Mode", NOT "PLAY IN VR".
Advice
Keyboard and mouse operation is a little difficult compared to tracked controller. So I recommend you to get used to it on Non-VR mode first.