The process of rendering out 360 stereoscopic videos and then importing into a new scene

I have a Unity scene which is quite detailed and causing lag when running on the GearVR. Since the viewer does not interact with the environment I want to render this to a 360 stereoscopic video and then import it into a new Unity scene where it is projected onto the inside of two spheres (one for each eye). That way I can re-introduce audio tracks to allow for spatial audio through head tracking. If that makes no sense, I've attached a little diagram.

I have found bits and pieces of...

The process of rendering out 360 stereoscopic videos and then importing into a new scene