The thing I liked about SUPREME is that it would have a "new" story and an "old" story. They were actually all new stories, but the back-up stories were made to look old. The old story would tie into the new story somehow. I saw this as a road map to how you could do Superman comics that used the old stories, but had new stories that tied into them.
Of course, Alan Moore made it easy on himself by writing the old story to have the right ideas and themes in it, that would make it fit with his larger story. But I'd bet that if he had been encouraged to do so back in the 1980s, when he was still on friendly terms with DC management, he could have pulled off this magic trick with actual classic Superman stories and his own stories that referenced them.
Grant Morrison did the same sort of thing with ALL-STAR SUPERMAN, where many old stories are referenced in his story. It's just that you don't have them identified in the comic (not even an editor's note). Someone should go through the entire work and annotate every page, identifying all the references and similiarites to classic Superman stories.