Modifying save event notification

I’m cancelling the save event based on the presence of particular content on a node, yet still see the save success notification - the save is being cancelled (I can’t see it in the node audit trail), yet the API response shows success.

If I hit save and publish, I get back the cancelled by 3rd party notification.

How/were do I override the save notification to display custom text on cancel?


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/71207-modifying-save-event-notification