In my professional modeling of a single project, I normally use several SU models.
As an example, one for the site and the other for the building. When I use this structure I import the building model (Child) into the site model (Parent). There are times when I desire that the building model have section planes that I will use in the site model scenes.
I would like to request that Section Plane attributes (notably “Active Cut” Enable/Disable) of the building model be remembered in the saved site model scenes and survive “Reloading” of the building model.