Will I run into performance issues using VR since normal mapping doesn't work?

Unreal Engine typically uses Low Poly Meshes and makes heavy use of Normal Mapping. But Nomal Maps don’t work in VR and depending on your Depth Perception (may vary from Person to Person and can be shifted more toward Parallax or Shape-from-Shading Perception) may look really awful and will totaly break presence. If you really want to do good VR with Unreal 4 you have to work with a much higher poly count. My Question now is: Will i run into performance issues since UE isn’t optimized for that?