Designated Throw in spot?

[TwoDot]

In our association meeting, we had an interesting discussion of the designated spot. This is the three foot area that the player must keep one foot over the spot. The opinion of the group was to allow 3 feet to start at the point outside the player so if the player moved right the three foot area starts the players left side - 3 foot one way, not 1.5 feet from center.
Any comments? How do you handle this, not that it happens very often at all.