Hey,
Samsung Galaxy S6 advertises OpenGL ES3.1 support, but it doesn’t have more advanced features ( ANDROID_extension_pack_es31a). Unfortunately, because of this UE4 uses OpenGL ES2 fallback, and thus doesn’t use instanced drawing.
Since instanced drawing is supported in OpenGL ES3.1 core, renderer should use it, even if Android extension pack is not available.
It would be good to have this, because GearVR development is very demanding, and it would be good to exploit every opportunity to squeeze some performance.