What is the main purpose of the invocations at the beginning of Shri Sai Satcharitra, as described in Chapter 1?

According to Chapter 1 of the Shri Sai Satcharitra, the main purpose of beginning with auspicious invocations (Mangalacharan) is a traditional practice for ensuring the obstacle-free completion of a task. The author states that the reason for this auspicious beginning is the removal of all obstacles and the fulfillment of the desired goal. To this end, salutations are offered to various deities like Lord Ganesha, who holds an axe to destroy the obstacles of devotees, and Goddess Saraswati. This practice is adopted to obtain the grace of the desired deity and to attain auspiciousness for the successful writing of the book.