Siteworks is a pending question for Revit since long time ago, and Site Designer isn't a consistent solution yet. Whilst we wait for true site tools to come, it would be worth to enable join topography and floors. Yes, of course, pads can make this, but their geometry is still very simple, they can only be flat or have a single slope.
If we could change height for points or edges, then the topography tool would even be useful