Ok last attempt here. I significantly narrow down my initial post to this:
UE4 claims to support various audio formats (mono, stereo, surround, Ambisonics) and binaural reproduction for headphones. Using mono or stereo formats it is obvious that the reproduction is pseudo-spatialized (calling it 3d stereo?). But when you use surround or Ambisonics formats you are supposed to get a fuller around-the-room sound experience. I.e. as you move your head around the sound source you should hear more or less of the front/rear/etc audio channels. So how can someone use either of these formats in UE4 in order to get this result in a VR project? If you can point to some documentation or ideally tutorial I would be so grateful.