dx.factory supports the following editing operations upon the Performance Part Objects within the Tree View of a Child Window:
To access all features other than Set (which you do via "Drag and Drop"), right click over a Performance Part or selection of Performance Parts to activate the Performance Part 's Context Sensitive Menu.
If Voices are present in the current file, then a User Voice from the same file can be dragged onto a Performance Part to set the Voice used by the Performance Part.
Please note, the drag operation for this is COPY only. You cannot MOVE a Voice onto a Performance Part.