I would trust a field Engineer over a random public forum person.
Call Supplies, they are the only ones that would have access to that official information and the process to do so.
Xerox has always including return shipping labels in the box of anything they wanted you to return the old one with. Anything else is picked up by the FE/CSE when they are on site.
I probably should have tried to put this in another section. Our FE tells us now that the plastic cases that the Restring wire for the igen does not have to be sent back to Xerox. Is this the only item that Xerox does not want shipped back? We still send back the fuser rollers. That's about it. Does anyone know?