According to Acton’s The Last Medici, in the 1670s, Grand Duke Cosimo III de’ Medici (as well as his wife) both attempted to have their eldest son, Ferdinandino, internationally recognized as the heir to the still-childless and unmarried Duke Charles V of Lorraine. Ferdinandino, through his mother was the nearest male heir of François II, since his mother was the eldest child of the daughter of Duke François II.
However, Leopold I, Holy Roman Emperor, not desiring Lorraine to revert to France, married his own half-sister, the Dowager Queen of Poland, to Charles V.
What if, by the Treaty of Nijmegen, Grand Prince Ferdinandino was accepted as the heir to Lorraine? Also, the Dowager Queen is either barren, or doesn't want to go to Lorraine. So to allay Leopold’s fears of Lorraine in the French sphere of influence, it would be more probable that he would marry one of the Neuburg princesses proposed for him, since I doubt, a union between Lorraine-Tuscany and Portugal would still be acceptable (with the other proposal being the princess of Beira), than the Bavarian princess he married OTL (since she was the sister of the Dauphine).