form binding with concrete List implementations

when using form binding on a bean declaring a concrete List implementation as return type (e.g. LinkedList, ListModelList), a FormProxy cannot be created for this getter.

exceptions like this are thrown:
java.lang.ClassCastException: org.zkoss.bind.proxy.ListProxy cannot be cast to org.zkoss.zul.ListModelList

To reproduce run the attached example.
So far the bean may only declare the List interface as return type.

Is there a way to enable such a case? Or if not - throw an exception giving an additional hint what needs to be changed?