Oh but wait, there's more.
Oh but wait, there's more. After disabling the "keyless entry" feature, which is required in order for "PIN Access mode" to function, the dash will display "Access Key Disabled" when you press the Start button. You may think you've broken something. In fact, the Subaru Help desk, the Subaru escalated help, and even the Subaru dealer I spent an hour at won't know that this too is part of the same feature and REQUIRES starting the vehicle with the key fob pressed up against the Start key. Not just as a solution to a weak key fob battery, which is also good to know, but as an even lesser know feature to prevent anyone from driving your Subaru away if they happened to crack the PIN Access Code to gain entry, but are not intimitaly familiar (even more so than your local certified Subaru mechanic) with the Operating Manual's subtle mention. RTFM man.