Vrsumo2017 yea, sorry i dont remember if it was you or another one in your team, but they shared that perhaps the first implementation of this would be to simply allow images as backgrounds since the process of playing two separate video layers might be system intensive for current standalone headsets or medium computers, so these type of image renders would work great to start off with.
I'm going to start looking through the unreal asset store and see what I can put together next for an interesting location.