Double pressing the super key should always bring up the app grid.
Currently when you double press the super key it launches the app grid ONLY if you are not already in the overview. When a user is in the standard overview and double presses the super key it will exit to the desktop. This is already done by just a single press of the super key and is unnecessary.
This inconsistent behavior prevents users from easily accessing the app grid with just the keyboard if they don’t press the key fast enough, or forces them to cycle through overview modes again if they are already in the overview without the app grid wasting time.
Thanks to the GNOME team for being open to suggestions and creating such a great desktop environment!