4.12.4 is out of the way and hopefully now someone can look / comment on these issues :o
HISMC actors get no lighting: [Gear VR] HISMs don't receive any lighting (neither baked nor dynamic) - Rendering - Unreal Engine Forums
Foliage doesn’t render: [Gear VR] Foliage doesn't work on the device - Rendering - Unreal Engine Forums
Thanks beforehand