i'm using mostly shared calendars, so it would be nice to have an option to enable notifications about synced items. maybe even in a configurable verbosity e.g.:
- summary: added 3 items, deleted 1 item, modified 1 item
- added: vacation from 2017-10-31 till 2017-11-05, meeting with $person on 2017-11-06, birthday of $person on 2017-12-12
- deleted: BBQ on 2017-10-15
- modified: party on 2017-10-13
so you know that/when other people modify the shared calendar.
i'm not sure if it's possible to detect which item a user clicked on in the notification, but there could be an action opening the clicked event in calendar. or just the first one.