The text mentions different types of biographical writing. How do they compare in terms of their spiritual benefits?

Chapter 0 outlines a hierarchy of biographical writing based on spiritual fruit. Writing about worldly figures like poets is considered a worldly service with importance limited by time and space, ultimately yielding no spiritual fruits. A step above this is writing the biographies of many saints; this is a form of Guru service that does provide spiritual fruits, but it is considered one-sided or partial. The highest and most certain service, according to the text, is to write and devotedly study the biography of one's own Sadguru. This specific practice is said to grant the ultimate spiritual goal and the fruit of salvation, making it far superior to the other forms.