Ah ok, i understand.
I'm afraid this is more difficult to achieve, because each side of the facade is an independent RC object, which cannot be connected with its adjacents.
An option would be to create a specific object for the corners, which the exact shape to fill the gap.
I'm not sure if it would be generated automatically by RailClone, because the facade style is already a bit tricky. I will consult with our RailClone specialist.
Meanwhile, you would create the pieces manually, taking one of the facades, converting to mesh, slicing the geometry and adjusting visually.
I've included a screenshot, so you get the idea.