You name an avant-garde brand of note – Saint Laurent, Rick Owens, Moschino, Comme des Garçons, Yohji Yamamoto, Jacquemus – and chances are they’ve been overtly influenced by a shoe designer extraordinaire, André Perugia. Cage heels, no heels, disappearing heels, under-slung heels, corkscrew heels, float-in-the-air heels, needle-thin fetish heels – you name it, if they’re…