Need Help Managing Timed Attractions

Hello, I work for a reservations team where we book field trips/groups. I'm having some issues, specifically with our timed attractions. We have two theaters that run from 10:30 AM to 4:30 PM on intervals of thirty minutes, and we prefer to pre-sale these attractions to groups so the balance can include both admission and attractions. We also have two "all day" events. When the group sale page is created it only has one itinerary, and if you attempt to add a scheduled event to this itinerary it includes every member of that itinerary in the scheduled event.


Our current workaround is to splice the group into multiple itineraries, but we have to be cautious to remove the exact Type and Count of visitors from that primary itinerary or we could double charge admission or have different Types with different admission prices. When considering a group of 300 visitors this becomes a time-consuming chore, since our maximum capacity on a show is 28, we would be creating 11 itineraries, and it becomes more complex when guests have a scrambled amount of timed attraction tickets for their groups. 


I also considering creating "Custom Items" and manually putting the price, but that would result in visitor numbers for attractions being incorrect in reports. It also did not affect the capacity of the Scheduled Events that are scheduled in the same location at the same time, so there is a possibility that a show could be oversold by a different department as it displays those spots as open. 


Any help would be appreciated!