A new Disable Reminders setting on a source calendar stops the copies Keeper.sh makes from it from firing reminders of their own. The original event still reminds you as usual, and its copies hold the time without alerting you again.
Before this release, an event copied into two or three other calendars could set off a reminder from each of them a few minutes before it started. With Disable Reminders on, you hear about the event once, from the calendar it came from.
The setting applies to copies on Google Calendar and Outlook. On Google Calendar, copies opt out of the calendar's default reminders, and on Outlook they are saved with the reminder turned off. Turning the setting on or off updates copies that already exist on the next sync.
Disable Reminders sits with Mark Events as Private in a source calendar's sync settings, and like the other event filters it is part of Pro.
What a copied event shows lists the other settings that shape a copy.