This is more a GDL-, but in the intention also a user-interface wish, so I post it in this list.
I have often to place objects (windows, doors, labels) with just one or two different parameters of their custom parameters list. It would be very useful, if this objects would have a small section in the information pallette, in which I could control this parameters. As width and height of the objects.
It could be solved by a certain e.g. 60 pixel high info-user-interface-script of the gdl-objects. So each developer of objects could decide which parameters are available there. Ore could post status informations about the object.
It would be downward compatible. If there's no script, there's no info-section.