as jon mirtchin suggested:
"Not sure if anyone at Graphisoft has considered parametric IFC to GDL, but I'm sure it would be more likely if users were demanding it. "
so here is the wish for archicad, the posibility to read ifc's parametric representation and properly convert them into archicad elements.
he has developed a plugin for Revit that precisely does this: https://www.youtube.com/watch?v=wpYL9zyRdcU
also more IFC's more "intelligent" object representations would be wellcome in archicad IFC import/export workflows. Nowadays, ac21, is not able to import "IfcRevolvedAreaSolid", for example.