It should be possible to use PartsLink attributes in the query builder to create reports.
Currently it is only possible to build reports with the attributes that are connected directly to a type. It is not possible to create a report that lists the values of attributes defined in the classification of a WtPart.
Particularly this is required to create report templates with PartsLink attributes to make it is possible to use this templates in the Related Object Search. This is needed to find objects that are related to another object with a specific value in a classification attribute.