How does writing a Sadguru's biography compare to writing about worldly figures or a collection of saints?

Chapter 0 draws a clear distinction between different types of biographical writing. Writing about worldly Gurus is seen as a worldly service whose importance is limited by time and space and is often rooted in self-interest, thus not yielding spiritual fruits. Writing biographies of many saints is a higher form of service that does yield spiritual fruits, but it is considered one-sided or partial. The text states it is difficult or impossible to reach the ultimate spiritual goal this way. In contrast, writing the biography of one's own Sadguru and studying it devotedly is presented as the supreme and most certain service for achieving salvation.