I customized the list form with PowerApps and put the following code in the OnEdit event of the form:
The notification shows up only when I edit item 7. As you can see on the video below, I edit item 7 and the notification shows up but (if I don't hover it or close it manually) it only disappears after the native delay (about 30s I think) WHATEVER YOU DO (change item, create new item, display other item, etc.):
This is a real problem because in my case (and in a lot of cases I guess) a notification refers to the selected item. So if the user doesn't close or hover the notification it is still displayed even though he goes to another item (which is very disturbing).
My opinion is that a notification should close when a form is hidden (whether you click outside the form or you click the CANCEL or cross button).
Note: I do not consider this should be treated as an idea as, by design, I guess a notification should be hidden when a form is hidden.