How to use Target Eye Unity 5.2.2p1?

I just downloaded Unity 5.2.2p1 in order to try out this feature that was announced:

VR: A camera can now target the main display backbuffer in VR mode by setting "Target Eye" to "None (Main Display)".

However, I am unable to get the main display to render something different from my DK2. The way I have the scene setup now is that I have two camera: VR Camera and Main Display Camera that are looking at different things. The settings are default except for Depth and Target Eye. For the VR Camera, the depth = -1, and Target Eye = Both. For the Main Display Camera, the depth = 1 and Target Eye = None (Main Display).

Do I have to do anything else for the Main Display Camera to render on the main display? I am wondering if anyone else has gotten it to work.