It sounds like staying in the Chavadi was a terrible ordeal for Amir. Were there any benefits to him staying in such a difficult place?

Yes, despite the extreme physical hardships, chapter 22 explains that there were profound spiritual benefits for Amir Shakkar. The primary benefit was the constant company of Sai Baba, which the text calls the "Great Prasad." Because the Chavadi was his assigned place, he received Baba's vision (darshan) automatically and effortlessly. He would see Baba pass by on his morning alms round and again in the evening. On the nights Baba stayed in the Chavadi, they were separated only by a plank door and a curtain, and they would talk together after the other devotees left. This close companionship was considered a rare fortune.