Requests about properties only work with labels – as it is written in the documentation. (And zone stamps as they are working like labels). Properties should not take any effect on the 2d display (and 3d model) of any objects – except the visual override option outside GDL.
Everything which changes the symbol or model must be the library parts parameter – properties are just additional things attached to the element to store information about the library part.
Gergely Fehér
Team Leader, Library Team
GRAPHISOFT SE