At the moment it is not possible to disable positional and/or rotational tracking for any given VR camera. This can lead to issues when there are multiple VR cameras that need to function in different world-scales.

Reproduction Steps:
1. Run the reproduction project for VR
2. Move your head around
3. Note that the skybox camera setup in this scene moves at a vastly different scale, because it's having positional tracking applied

Workaround:
Select the object "Camera Parent" and set the transform scale to 0,0,0 -this will result in the camera in the skybox having tracked data applied at a scale of 0.

Expected Result:
Users should be able to either pick and choose between the following tracking modes on a per-camera basis:
* Positional & Rotational
* Positional Only
* Rotational Only

or alternatively have a scale control value, defaulted at 1, so that users can adjust the scale of the positional tracking being applied (setting it to 0 to turn off any positional tracking).