Whether or not the fans think “Once Upon a Time in Hollywood” is the greatest Quentin Tarantino film of his career, the director himself seems to think the feature is his magnum opus. How can we be sure of this? Well, over the course of the various podcasts and interviews he’s given, it’s clear the filmmaker thinks ‘Once Upon’ will be the film that leaves the biggest mark, and though the feature was released in 2019, he still has plenty more story to tell in that universe.