This is key and especially so now that, with SU 2020.2, tags style can be overriden in a viewport.
Now, visually, everything works in a pdf, but if you are collaborating with engineers, clients and consultants, you have to use DWG (if you’re not in a BIM workflow already).
In that DWG file, even if the property line is red and dashed, if it is in the same viewport as the buildign it is still going to be exported in the same layer as the building, section line, landscaping, and whatever else is in the model.
Visually it works, but structurally it’s a mess of a DWG and collaborators can’t isolate the information they need from the drawing.
I don’t see how they work different in Layout. In Layout they are corresponding to 2D geometry. That 2D geometry is exported to CAD in the viewport layer. However, Layout can access Sketchup tags and alter them, and override their edges display since 2020.2. It means it can identify which edge is in which layer. It’s just a matter of exporting each edge into each layer, into the CAD file.
The question then would be how to export Layout’s native Layers. And here I’d propose they are exported to the DWG/DXF Layers as the rest of the SU tags. And if there’s duplicate name just add an prefix LO_ or something.