Hiya Emily!
Welcome to planDisney!
Mickey's Not-So-Scary Halloween Party is tremendous fun and I consider it one of the best events of the year.
I love that you are thinking strategy so I wanted to make sure I got the right information. I reached out to a Cast Member and was informed that guests with special event tickets are ineligible to purchase
Disney Genie+ service on their event day. This also includes the purchase of
Individual Lightning Lane. A regular Park ticket is required and if needed a Theme Park Reservation as well for the purchase of these extras.
You will probably find though as the Park starts to empty of regular Park guests wait times drop. I suggest you use this time to enjoy as many attractions as you can or have a lovely meal and be ready to go for the official party starting at 7:00 PM. Don't forget to get your party wristband at the front entrance when you enter! I also want to make sure you know about the
Foodie Guide for this year's party! That Candy Corn Milkshake looks like a yummy sweet option to keep me awake for the party. Sweet potato cornbread nuggets sound very intriguing.
I hope this helps and you have a wonderful time! Let me know if you have any more questions!
Happy Planning!
-Nimmy