After thinking about this for a while, I'm not sure I buy into the fact that all formatting is done by the phone. One day it was formatted with the parentheses and dash, and the next day (when I switched to the Obi) it was formatted differently. My actual phone did not change, just the provider. So, not all the formatting is done by the phone, perhaps some.
By pressing the one button, I could add a leading '1' to the beginning of the number. But since the Obi already adds a leading '1', it actually displays an invalid phone number, I can't redial from the phone from the Obi, since it now adds two preceding 1s.
Is there any way to ask a firmware programmer this question?