I wonder if it would be a good idea to show Luke’s lightsaber retracting in the final Academy flashback. To make the point of the scene more clear and dispel the misreading of the movie of Luke trying to kill Ben for having a bad dream. He’d have to re-ignite it when Ben attacks him, too, of course.
Luke clearly changes his mind about killing Ben at the last minute. And it needed to be on so Ben would realize, “Oh shit, Luke found out that I’ve turned to the dark side and he was gonna stop me!”