...
The new is that if you supply a roughness and/or specularity map, you'll start to see environment reflections too, even if no envmap is explicitly defined
Cubemap Generation
The way I did is was by making a generic area, take screenshots in all 5 directions and some hand-made sky/ceiling
This is for the city exterior:
At that point, I embedded the some lightsources for reflection, but shouldn't be there anymore with actual specular lighting
You can try yourself if you put this in your override:
But you'll need 8193.14 build for now