SteamVR Camera Fall

I am trying to have "weight" added to the VR player. The result I'm looking for is when the player physically walks and no longer has collision under them virtually the player will fall. Similar to Richies Plank Experience. I can get the entire rig to fall when no collision is detected however if the player physically moves in the dedicated play space off an edge virtually the result is not the same. I'm surely missing something, but I am lost at this point.

 

https://forum.unity.com/threads/warning-general-vr-questions-will-not-be-answered-here.553759/