I'm using my Macbook while it's connected to a larger display. I'm mostly working off the larger display. Is there a way for notifications to be displayed on both screens simultaneously? I'm specifically concerned about Slack, but if there's a way to do this for all applications, knowing how that works would be much appreciated.
No, notifications are always only displayed on on the display designated 'primary'. (The one which has the white menu bar line on it in System Preferences → Displays → Arrangement)
