Disable Steam notifications in-game only

It would appear that there is no way of disabling notifications in-game only, while still keeping the steam community enabled in-game.

Either notifications need to be turned off globally (View -> Settings -> Friends -> Uncheck all the "Display a Notification" check boxes), or the steam community needs to be disabled in-game in order to prevent me from receiving notifications in-game.

View → Settings → In-Game → Enable Steam Community In-Game (remove tick)

If you go in-game and do shift+tab, you get that odd overlay menu. in the friends pop-out there is your name, and a settings symbol next to it.

click it and you get a "friends light settings" menu

go to the Notification tab and uncheck everything