Disabling SteamVR's 'CameraRig' and re-enabling default camera during play test

I am developing in Unity with the SteamVR plugin and I have gotten everything working nicely with the headset and controllers so that when I press 'Play' to test, everything runs as intended.

However I have gotten to a point in development where sometimes I want to test things with a default static camera. So I delete SteamVR's prefab 'CameraRig' in my scene's hierarchy and make sure the 'Main Camera' is enabled and tagged as the main camera.

But every time I press the play button, it...

Disabling SteamVR's 'CameraRig' and re-enabling default camera during play test