oh thanks for the leads on this topic! it's funny, our submission was genuinely one-half an epistolary work, and inspired by epistolary poetry (in our case, largely Bernadette Mayer's Desires of Mothers), but the letters themselves were not written primarily as poems (barring a few exceptions). that said they do meet that criteria to a lesser or greater extent... i think we're going to continue to explore this since it's an area we don't quite understand yet lol.
that said i can certainly sympathize with the narrator's hesitation to let susu read her poems... i've found even when i am not necessarily writing about someone or to someone, if they're on my mind when i'm drafting or revising, it's not always something i want them to see. or at least i'm aware of it being very vulnerable to let them see.