Appointment Reminder - add 15, 30 min before and "At Scheduled Time"

Hello, it would be helpful to have more options for appointment reminder.
At 1 min before, 15 min, 30 min, At Scheduled Time (or 1 minute before)

Often, working with tickets I will run a script or start a process like Rebuild Raid Drive and want to have a reminder to check on the process. Thank you for your consideration.