Apple may still have long-term plans for titanium in future iPhones despite shifting the iPhone 17 Pro lineup to aluminum. According to a new leak from Weibo tipster Instant Digital, the company is reportedly researching an upgraded version of titanium that could appear in upcoming models. Apple had previously promoted titanium heavily in the iPhone 15 Pro and iPhone 16 Pro for its lightweight yet premium design, but reports suggest the switch to aluminum in the iPhone 17 Pro was made to improve heat management during intensive tasks like gaming and AI processing. However, titanium is still believed to be…