Warning: the following contains canon spoilers from the novel: From A Certain Point of View.
The theory of Boba Fett being the one who fries Uncle Own and Aunt Beru has been busted. That’s a bit disappointing, but the origins are still cool.
The infamous “No disintegrations” comment refers to a time when Fett had a confrontation on Coruscant, with a few rebel spies. The spies attempt to wipe Boba Fett out with ion disrupters… little did they know Fett had a weapon accelerator. The only thing left at the scene was the standing bounty hunter and three piles of ash. Vader refused to pay out the Bounty to Fett because he prefers to have the corpses intact.