Given that the Guru biography by Shri Samarth Sadguru Dattatreya Maharaj of Balekundri is considered more famous than the one by Saraswati Gangadhar, what are its main themes?

This question contains a misleading premise. According to the Preface in Chapter 0, the Guru biography written by Shri Samarth Sadguru Dattatreya Maharaj of Balekundri is mentioned, but the text explicitly states that this biography "does not yet seem to have been printed or published." Therefore, it could not be considered famous, and its main themes are not discussed. In fact, Chapter 0 notes that the biography by Shri Saraswati Gangadhar is more famous than the one written by Shri Samarth Sadguru Vasudevanand Saraswati Maharaj, not the unpublished one by Dattatreya Maharaj.