With the discussion about the paid FP, I don't know why they don't make all rides like the express toll lanes on highways. Each ride would have a free standby line with a posted wait time. Then, there would be a paid shorter line. For the paid line, there would be a posted wait time and a price. The price would be dynamic based on the free standby wait time, the paid wait time and the difference between the paid wait time and the standby wait time.
There would be no pre booking. When you arrive at the attraction, if you want to pay the price for the paid line you scan your magic band, card or phone and you get charged with a payment method tied to your account. The MDE app would show both wait times and the current price for the paid line.
This way there is no pre planning and the paid line never sells out. The price just keeps increasing until it isn't worth the time saved. When too many people are joining the paid line, the price would have to get ridiculous so that people stop joining until it clears out a bit. I'm talking truly ridiculous prices like $50+ per person per ride.