Sorry I don't own any Saint Laurent flats but I have their tribute sandals in smooth leather and they fit perfectly true to size. I'm an Italian size 35 (Valentino, Gianvito Rossi, Salvatore Ferragamo) but I don't own any of the ones you mentioned.. Not sure if this is relevant/helpful for you..Not one person can tell me if they fit true to size?
Just going to bump this thread as I'm currently looking at a pair of patent leather Saint Laurent flat oxfords and wondering if they run true to size!
Hope someone can help!!