I have noticed other games doing this on steam currently (made in Unity). So I figured I would ask.
Best,
Spiris
One of my collaborators actually managed to dig this up on another forum!
The solution was extremely simple, but undocumented as far as I can tell.
All we had to do was add the command line parameter "hmd=steamvr"
The overlay and menus will be accessible with the left controller menu button, so if your game binds it, it may need to be adjusted appropriately.
WARNING:
If you use this method, the HMD module for Oculus’s VR implementation will be unloaded. This may have some adverse effects on the experience you are aiming for. In our case the hands switched sides, leaving the left hand in the right hand and so on, we also had a number of issues with our input bindings being assymetrical. I initially questioned why this was not documented better and I guess I got my answer. It appears to be that UE4 does not yet have full support for a Oculus HMD launched through Steam.
So I guess this is just a [Feature Request] with some emphasis of priority because there are players out there right now enjoying support for this feature in games, not ours, made in Unity.
Edit: Update regarding discovered difficulties.