The VR support in Unreal has been great. But there is a new requirement which could benefit VR a lot.
What we need is a new type of render target, which act like a normal texture on materials. But this texture has two internal textures (say textureL and textureR) inside. Only one texture is rendered in normal rendering. But in VR rendering, each texture will go to each eye (textureL is rendered in left VR view and textureR is rendered in right VR view). This way, we can see the 3D image (the image pop out from display surface) in VR.
This feature could not have a work around from outside. We have to support from the rendering engine. If we can have this, we can enjoy thousands 3D video and 3D movies in VR which will be great experiences.