My Pope Tamás Bakócz thread (actually Kellan's but never mind) got me thinking about the logistics of crusading in the 1500s. From what I gather, while there were plans for crusades for centuries after the main numbered crusades, they never happened due to the double-whammy of the Italian Wars and the Protestant Reformation.
Assuming the Italian Wars don't happen, or at least don't happen on the scale they did OTL, could a crusade (likely against the Ottomans) happen? Would a TTL pope approving the sale of indulgences for a crusade go over differently compared to the OTL reasons?