So far a notification has been mainly to give the user the feeling that his entry was submitted, stuff like that.
Thanks to the compount actions you can make notifications more specific, more personal, more communication.
To really communicate with the user and to give the user time to take in the message, the timeframe in which the notification is visable is too short now.
It would help me if I could set the length of the visibility of a notification.
Are you wanting only 1 button press?? If so have the button set up the notification as well as a toggle thats shows they entered and make the button visible based on the toggle being false, when it is true the button disappears and you will only get one entry. If you dont care then have the google sheet just use the unique function on the people that did enter and you will only see the name once.