Hi Logan! Welcome to planDisney!
Oh boy! You're only a couple of weeks away from you're magical
Walt Disney World vacation! Now is the perfect time to iron out any last details before your trip begins!
Disney After Hours is one of my favorite events to attend. Not only do you get to explore the parks at night, but you're able to ride many more attractions with minimal wait times. Since you are visiting during Spring Break, it will be nice to have a change of pace from the busier park days.
Logan, you are correct.
Disney Genie+ is not available to use during After Hours events. Since you are able to enter the parks starting at 7 PM on this night, you can theoretically purchase Disney Genie+ for the last couple of hours that the park is open. You will be very limited to what attractions are still available during this time and how many Lightning Lane selections you will be able to make. In my opinion, I don't believe the cost of the service will make sense for just a short amount of time.
I would utilize the time you have before the event starts for other activities you have planned. This may include grabbing a bite to eat or shopping for merchandise. Once the event starts, that is when you should dedicate your time to as many attractions as you can fit in. The wait times should be minimal if any at all.
Disney's Hollywood Studios is the perfect park to attend an After Hours event at. There are numerous attractions to choose from and many different lands to explore that are especially fun at night! You are going to have a blast!
Logan, I hope you have a magical time during your stay!
See ya real soon!
Greg