Question: In the Agenda view, is there a way to avoid events being shown multiple times when they are assigned to multiple calendars?
Here's an example of Agenda view showing an event assigned to multiple calendars, with the event shown separately for each sub-calendar it's on.
There's a simple way to change this display.
The calendar administrator can adjust the setting display choice for multiple calendars per event:
If the Display option is set to Multiple Boxes, then the event is listed separately for each calendar it is assigned to.
When the Display option is set to Striped, the event will be listed once with the sub-calendars indicated: