I favor the approach of making a PTP for the day and using the optimizer to determine the best FPP reservations - see Making Optimized Personalized Touring Plans with FastPass+
I don’t like the use FPP early and try to get more at the kiosks for two reasons. First, you are using valuable FPP reservations at times where they are not necessarly giving you that much of a time savings. Second, you are gambling that there will be FPP reservations available on the day that will be useful for you. However, my opinion on this may change now TouringPlans is tracking FPP availability and may soon be incorporating the additional FPP opportunities into the Optimizer logic.