HTC VIVE - Large City Scene - Shadow Flickering

I am creating a large city scene with skyscrapers, streets and traffic. The player is set on top of a building.
Later in the process I've noticed some z-fighting and shadow flickering in the background using a FirstPersonCharacterController on my artist workstation and of course with a Vive CameraRig on the Vive workstation.
Fixing these issues with the FPCC was easy (Near/Far Clipping Planes & Shadow Near Plane Offset), but I cannot get good results with the Vive CameraRig. At first the...

HTC VIVE - Large City Scene - Shadow Flickering