Hi Grant,
Thanks for your interest in Syncfusion products.
We have analyzed your scenario. As per our current architecture, the ScheduleControl does not have the support for customizing the order of appointments by using its label (Important, Business, etc.). By default, the appointments will be ordered based on the time periods and the label is used to paint the different colors on appointments. Please let us know if you have any other queries.
Regards,
Piruthiviraj