I give up! Just tried to book (online) the Firework Desert party in September, and its all booked up.
I have been watching the reservation site for a while, and today was the first day I have seen September available. I tried every night I'm there (3 weeks) and no joy.
I'm getting desperate, ( failed to get a seat last 3 years) I might have to book a Disney Resort to get extra time to book.