Saving, when instant, does not need to notify the user. Not every action needs to notify the user.
As seen in the article, do we need a notification following a click to every checkbox? In most cases, the user should assume that the action is completed the moment it's taken. If not, you can add an inline loader and show a regular, maybe modal error if it happens.
"Save" actions, with the exceptions of large data, does not need further UI. Particularly the circle should be seen as a marker of the current state, not as a way to tell whether your action has completed successfully, so you shouldn't view it as a "10x more subtle notification"
