Michael,
I doubt that we would enforce it differently if we saw the same thing.
But I actually believe the language I quote from the text of the OBR rules describing a pitcher's illegal move does mean something.
And, were you to use your imagination, I'm guessing you could picture a move where the pitcher does a "double step" off of his pivot foot - not a "normal" 3rd to 1st move, mind you - that you would deem violating both the letter and the spirit of the balk proscriptions as well.
Go ahead. Wherever you are - your family room, some near-campus bar trying to pick up coeds, the library, whatever - just try it.
Almost like a preliminary "jab step" towards 3B, only with the free foot instead of the pivot. Just enough to gain "distance and direction" in the direction of 3B with the free foot, but not enough to compromise your balance nor the leverage of your pivot foot as you then quickly "wheel" to 1B to pick off the runner there.
As the famous umpire Thomas Stearns Eliot once sagely observed,
so I may not be conveying what I'm envisioning in a way that creates the same picture in your mind. But, if you believe what I'm picturing is legal, we'll just have to agree to disagree.
Because, of course, I'm right and you're wrong.
JM