Exousia CAN be used symbolically: BDAG, Greek fathers, and Diodorus of Sicily support this

Against Keener and Ramsay's claim that symbolic authority is unnatural Greek: Anthony Thiselton notes most patristic commentators saw exousia as metonymy for 'sign of power' (Chrysostom, Theophylact). Irenaeus substituted 'covering' (kalumma) for 'authority.' BDAG lists this as a viable meaning. Diodorus of Sicily describes a statue with 'three kingdoms on its head' -- kingdoms represent someone ELSE's authority (her father, husband, and son who were kings). A strong parallel to 1 Corinthians 11:10.