... , once looking further into each applicant). But even in this instance ... many times it took each applicant with a 172 to attain ... /saving face to a prospective applicant, or their answer was far ...
I agree with the above comment. I think if you approach it just as how you mentioned it sounds like a great personal statement. Themes of resiliency, not giving up, overcoming obstacles- in my eyes- make you a strong applicant. Good luck!!
It seems you wouldn't write an addendum for this. Addendums are generally for things related to the applicant's life. Instead maybe just wait a few days while sending a polite email to the person.