When you subscribe to your roster calendar, it shows every service time (such as rehearsal, setup, etc.) as a separate event on your calendar, even if that's not a time relevant to your volunteer position. Honestly, this makes subscribing to the roster calendar feature useless. Of course I could not use the "times" section of a service, but that's helpful for people to see when each team is supposed to arrive, etc.

Have you considered just adding an "add to calendar" button for each service request?

Or at least make it so that when you subscribe to the roster calendar, it only adds the service and position to your calendar, and only once.