Wasn't there still a Medici branch in Naples? (Medici-Ottanjo) Granted their claim was pretty distant but if Charles VI expressly stated he intends to reclaim for the Empire/enfoff on the Medici of Naples he'd be able to stave off Franco-Spanish influence and maybe get more allies for the potential War of Tuscan Succession. Heck a conference could be made to avoid another war if the War of Polish Succession is that fresh.