I used to use OpenVR Input Emulator to do this, but it has become quite broken. I use Vive Trackers with my Oculus Rift to have full body tracking. I needed to use OpenVR Input Emulator to offset the Vive trackers so that they lined up with my Rift correctly. It would be great to see a feature like this implemented, as it has become quite a hassle using other methods.