Aside from the 'Shri Sai Satcharita' and the 'Brihat Guru Charitra', what other Guru biographies are mentioned and what is their status?

Yes, Chapter 0 mentions a couple of other Guru biographies but clarifies their less prominent status. One is a detailed, scholarly work by Shri Samarth Sadguru Tembhe Swami, also known as Vasudevanand Saraswati Maharaj. However, it is noted that this book had not become as famous and is in a different category because the Guru wrote it himself. Another biography by Shri Samarth Sadguru Dattatreya Maharaj of Balekundri is mentioned, but the text states it did not seem to have been printed or published at the time, making it inaccessible to the public.