I have already asked and they can not do it, and I publish here because my thread is no longer followed / =
I understand what you mean, however for windows, inside I can not do what I want, it is a walkmesh, more lights are in the layers and does not allow to add elements, unfortunately. The only place where I could add would be between the buildings and it would serve no purpose because in the background, they will be invisible, and in front, the hollow part of the walkmesh, add details will be difficult. For the grain, I agree on the flags they are a little too thick, however the wall we can see the details of the foreground later I do not perceive
And slatted have been thought for them big feet of the original 3D models haha