We tested with the colleagues in OOTB ( 11.1 M020) the behave of two cascading attributes in structure view .
The structure edit mode is not working. For example :
Both attributes we created are used in global enumeration value. If there is only one attribute than the drop down menu in the structure table view is editable. But when there are two cascading attributes connected with a rule the structure view can not be edited. The Idea here is: Possibility to support the cascading attributes for editing in the structure tree!
Please refer to the screen shots for more information.