If you—Graphisoft—were to allow GDLs to access the database of standard Archicad elements just like labels do, then add-ons like “accessories” wouldn't be necessary, and GDL would get a real boost.
Or conversely—labels can already access elements and their data. You would just need to enable labels to “work in 3D as well.”
One could also consider “merging” the two tools—that is, library elements and labels.
Open