I'm wondering something about this myself now. Say I wanted to farm PoS for the hilts and gear drops. If I don't touch the bosses, and exit and refresh using the LFD tool, will I be locked to the instance and be prevented to reset it as if I were to kill Garfrost on heroic? I know you can farm him all day long with that tool for the Emblems on normal, but can this be done for trash farming on heroic?