Prevent irrelevant notifications

Currently when an appointment falls within the scheduled notification period, all relevant notifications will be triggered.
For example if there are two notification setup one for 2 hours before the appointment and another 48 hours before, if an appointment is more than 48 hours away from a scheduled notification, only the 48-hour notification will be sent. However, if the appointment is scheduled within that 48-hour window, both the 2-hour and 48-hour notifications will be triggered at the same time.
In this case if a user is scheduling an appoint 4 hours before they will get two notifications at the same time instead of just getting a 2 hours before notification