Windchill object inheritance is a key feature when defining the data model for an implementation.
It is common that parent nodes get marked as none instanciable to prevent object creation.
However for configuration purpose it is essential to use these nodes to inherit the commonality.
Therefore Index and Access Policies should use the tree structure as is
Same is true for Search preference definition. It is not efficient neither intended to define each child class by it's own. Currently the non instanciable are skipped and automatically expanded in the UI which makes manual config impossible.