Thank you for the response!
I have no problem with writing an addendum. My concern is that most advice seems to suggest that one should only write a GPA addendum if there was a legitimate excuse for poor performance. Unfortunately, I have none and I'd rather not stoop to making one up, either. Is it acceptable to write a brief addendum with an acknowledgment of my poor performance, but followup with evidence of growth? Or is it better to skip the addendum and try to work this into a personal statement?
I believe that I have changed. I spent a year self-studying for the LSAT to prove to myself that I could meet a goal. That type of work would have been unheard of had I still been an undergraduate. I scored a 170. I felt that that score was high enough, in addition to my history of employment and time away from school, to justify continuing with the dream.
Thank you again for the response!