I'm using an AutoHotkey script for this. Someone made one for DOS1 and put it up on The Nexus. It works for DOS2, as well, without modification.
I modified my copy so that Show Sneak Cones is also a toggle, it shows a tooltip when either toggles (so I know which state it's in), and so it automatically quicksaves every 5 minutes. These toggles are not 100% reliable, though, so it would be better to have it programmed in-game.