I'm sure P & W's lawyers will agree with the OP in that "transient" excursions are regarded as unplanned momentary operational exceedences and should never be used wilfully or deliberately, let alone routinely. I'd be astonished if that were not so.A "transient" exceedence occurs in an unexpected event when the "Oh Christ oh !!!! oh dear" situation results in an input that produces a "woops!" response which is almost immediately cancelled/reduced. Seems pretty self-evident to me. And furthermore I'd hate to try arguing a defence of that practice against an FAA lawyer.