In my opinion , the documentary , From Star Wars To Jedi The Making Of A Saga is the Gold Standard of all official Star Wars documentaries to date.
What about Empire of Dreams?
I love Star Wars more, but Dangerous Days: Making Blade Runner is my favorite making-of doc.
Check out Hearts of Darkness (making of Apocalypse Now) and Burden of Dreams (making of Fitzcarraldo). Probably the two best “making of” docs ever made, both arguably better than the movies they document.