What role does Goddess Saraswati play in the composition of the Satcharitra, according to the invocations in Chapter 1?

In Chapter 1, Goddess Saraswati is invoked as the divine force essential for the creation of literature. The author acknowledges that without the grace of this Goddess of Speech and Mother of the World, he could not possibly write the book. She is described as holding the Brahma-veena and riding a swan. The author pleads for her to make him an instrument to share the nectar of Sai's life. Furthermore, Chapter 1 reveals a deeper truth by stating that Sai himself is Goddess Saraswati, holding the Omkara-veena and singing his own life story for the salvation of his devotees.