I find it hard to meditate on a formless God. Does Chapter 52 say anything about the importance of worshipping Sai's physical form?

Yes, Chapter 52 directly addresses the significance of meditating on Sai Baba's physical, or Saguna, form. It states that "Without entering the Saguna form, the light of the Self cannot be known." The text clarifies that the Parabrahma, which is without attributes, is "entirely difficult to understand." Therefore, meditating on Sai's physical form is presented as a crucial step. As Chapter 52 explains, by meditating immensely on Sai's physical form, the devotee's mind is purified, and eventually, the "subtle nature of the Self will manifest as the Saguna (form) vanishes." This suggests that worship of the form is a powerful and necessary means to realize the formless.