Nothing to do with feathering props but in line with the philosophy of training in case of a safety system ( auto feathering props ) not working . Emirates used to do all it's single engine work on the B777 in the sim with the TAC failed . The TAC is a computer that senses thrust diffencial between engines and automatically adds rudder to assist the pilot with control.
After a few real life engine failures where the TAC worked as designed and the pilots massively over controlled the aircraft . This training philosophy was revoked. ( till the next flight training manager anyway )