I've been saying this all this time, even before Wano I said that Luffy is ought to destroy Kaido's 1v1 record.
I think that act 3 will end with the worstgen defeat, then, Luffy and his friends will escape from Anigashima. During that period of time Kaido will fully recover from his wounds from the fight against supernovas, while Luffy will use that time to train even more-and come up with something more powerful than gear 4th (maybe gear 5th). After that, act 4 will be about the raid on Anigashima and will mostly focus on the war itself, we'll see Zoro vs King, Sanji vs Queen, Jinbe vs Jack, Flying six vs strowhats etc. While act 5 will be mostly about Luffy vs Kaido. I believe that act 5 will be 'Luffy vs Kaido', with Luffy revealing his new gear 5th in act 5.