The regular guiNode doesn’t work with the stereoscopic view. It’s possible to display things, but they won’t be in stereo. Instead you need to use the OculusGuiNode which is created in OVRApplication. Without looking deeper, I think it overwrites the original guiNode. I haven’t tried adding the fps and stats views to it, so I’m not sure what will happen.
I’ve however written a tutorial on one way of using it here: Free floating VR menu in jMonkeyEngine with Oculus Rift
There’s also a fully functional example in the repository.