The option to reserve an iPhone Duo for Apple Store pickup is starting to return on Apple’s online store, with the system live again in countries such as Australia , China , Japan , and South Korea . Unfortunately, our spot check revealed extremely limited availability right now, with few to no time slots available for all configurations. We only managed to find a single iPhone Duo unit available for Apple Store pickup in Australia on Saturday at the time we checked, as shown in the screenshot below, but it already disappeared by time we published this story. In other countries, such as the U. S. , Canada , the U. K. , and Singapore , Apple’s online store continues to advise customers to check back on Saturday, October 24 in regards to Apple Store pickup, so we expect the reservation system to resume in additional countries as the clock rolls over to Saturday time zone by time zone…