About a third of the way into Steven Spielberg's semi-autobiographical film "The Fabelmans," the titular family is visited by the wild and extroverted Uncle Boris, played by the legendary Judd Hirsch. Boris is the uncle of the family matriarch Mitzi (Michelle Williams), and the two seem to share a similar passion for the arts and for theatricality. There is some trepidation among the Fabelmans as to whether or not Boris should be allowed to interact with the teenage Sammy (Gabriel LaBelle),...