To be able to use a surface AND the perimeter as an automatic parameter in an assembly. When we do a takeoff of a surface, the system also calculates the perimeter. If I create an assembly and set "surface," I will need to point to the surface on the plan, but the software cannot automatically extract the perimeter to use it in the same assembly.
Example: Formwork for a structural slab. I would point to the surface, give it the thickness, and it would calculate the formwork below and the entire perimeter in the same assembly.