Yes, there is one button that plays the same note on the push and the pull. I think it is the one in the center of either the inner row or the middle row. All you do is retune that one button.
Yes, it does help - I remember now that I look at that chart.
On the middle row, there is a note that plays C on both the push and the pull. All you have to do to de-club it is to change the C on the pull to a D. That's all it takes.