Why does Chapter 11 of the Sai Satcharitra argue for the importance of worshipping a Guru with a physical form?

Chapter 11 explains that devotion to a manifest (Saguna) Guru is essential for a devotee who also has a physical body. The text posits that as long as a worshipper has a form, the Guru must also be in a physical form for worship to be effective, stating this is the determination of the scriptures. According to the teachings in Chapter 11, it is through meditating on this manifest form that loving devotion arises, which in turn allows the "bud of the mind" to open and bloom. Without this, the text suggests, true spiritual fragrance and nectar cannot be experienced.