Besides the Shri Sai Satcharita, are there other similarly detailed and comprehensive poetic biographies of saints from Maharashtra mentioned in the text?

Yes, the preface in Chapter 0 notes that while detailed works suitable for Parayans are rare in Maharashtra, there is one other major work besides the 'Shri Sai Satcharita.' This other text is the 'Brihat or Thorale Guru Charitra,' a sweet and graceful biography written by Shri Saraswati Gangadhar about Shri Samarth Sadguru Narsimha Saraswati Maharaj. The text explicitly states that the 'Shri Sai Satcharita' and the 'Guru Charitra' are the two preeminent examples, and beyond these two, no third Guru biography written in such detail is found, making them exceptional in their scope and importance for devotees.