A friend asked me: “Do you know a novel where the main character was part of a Sonderkommando?”
I could not think of such a novel.
Of course there is Borowski, but Borowski didn’t write a novel. (And the narrator is not part of a Sonderkommando, he is at most reflecting on the Sonderkommando.) There is Tišma, but the Kapo is not part of a Sonderkommando either, if I remember it correctly.
The Sonderkommando may well be outside the realm of fiction.