Oculus universal menu (UM) and signature check integration

We are building a Rift game with Unity 5.4 and found that we need to integrate it with the UM.

How can we know when the UM is active?

And how can we know if the user selected the Recenter App option?

According to the 5.4 release notes: The Oculus OVRPlugin signature check now happens only for non-development, release builds.

Does this mean that in order for us to release the app in the Oculus Store, we need to use the OVRPlugin to check the app signature ?

Thanks