The first time that Satan in Goray tells us that Levi, Reb Benish's son, is a supporter of Sabbatai Zevi is in part 1, chapter 9:
Levi, the rabbi's son, invited him for supper, for in his controversy with his father Levi lent his silent support to the Sabbatai Zevi sect. Gathered together were members of the inner circle; all the cabalists apparently sensed that the packman had something of interest to tell.
Satan in Goray, part 1, chapter 9: "Reb Itche Mates, the Packman"
And then the next several times Levi is mentioned, the book mentions his support of Sabbatai Zevi:
Common folk recited psalms, women measured the graves with wicks from which they later made candles to ward off death from the rabbi. Even the rabbi's son Levi, who belonged to the Sabbatai Zevi sect, forgot the differences with his father and joined the other visitors in the sick room.
Satan in Goray, part 1, chapter 14: "The Rabbi Forsakes His Congregation"
Levi, Reb Benish's younger son, he that belonged to the Sabbatai Zevi sect, was the master of the sacrament. Pale with the fear of punishment that he, not Ozer, was filling his father's place, the narrow glass in his hand trembled, and the wine spilled over his fingers[...]
Satan in Goray, part 2, chapter 1: "The Wedding" (translated by Jacob Sloan)
Why does Singer mention this so many times? This isn't brought up for any other character, such as Reb Mordecai Joseph or Reb Itche Mates, both of whom were supporters of Sabbatai Zevi; only Levi gets called out like this every time. What's so special about Levi that this is brought up so often?