an.factory supports the following editing operations upon the Voice Arpeggio Object shown within the Tree View of a Child Window:
To access all features other than Move, Copy and Set (which you do via "Drag and Drop"), right click over the Voice Arpeggio to activate the Voice Arpeggio's Context Sensitive Menu.
Preset Arpeggios from the AN1x Synthesizer Window can be dragged onto a Voice's Arpeggio.
Please note, the drag operation for this is COPY only. You cannot MOVE an Arpeggio onto an Arpeggio.