Did you solve the method you want? What do you mean by “trace”? Do you mean drawing edges of the property lines on the faces of the terrain model? Or separately overlaying the terrain? I’d do it in some way that does not cut or disturb the terrain surface. The property lines are good for guides to place geometry or adjust the terrain but they don’t represent actual 3d elements, and needlessly cut up your landscape, (and tracing by hand can be time consuming besides).
The Sandbox Drape command will place edges that are drawn in 2d onto your terrain model (or a copy of it).
Looking at your last comment, i’d draw edges over the image in 2d (on a flat face), then “drape” it onto a copy of the terrain (unique component). One could then erase the copied terrain outside the plot areas, make the plot faces translucent, and raise the plot model an inch or more above the terrain model. Give it a tag so you can hide it as needed.