I just tightened the nut on a non-keyed hole and its been fine for 4.5 years.

IMHO those stories about the ACS multi-position switch causing failures are MUCH overblown. Just install everything right and make sure you install the called for capacitor AND the called for diodes on the master relay and the start relay. I have not had any trouble and the factory SLSA's have been doing this for years without trouble, and as far as I know are still doing it. Now if you want the flexibility of turning the engine without ignition on (which I have never once found the need to do so) then use the toggle switches.