Regardless of where the Endor scenes are placed, couldn’t something be added to the crawl stating that Luke has been afraid to ask Yoda about the truth?

Luke has returned to the planet Dagobah to complete his training under the tutelage of the aging Master Yoda. In the ensuing months, he has yet to face the tormenting question of his parentage.

Not sure if this is any good, but it’s an idea. People often avoid uncomfortable topics. Once he knows Yoda is dying and that he’s only got one last shot to ask, he then asks.