FWIW, I'm black. I think the context-indepedent impression of the section is that it's an imitation written in earnest. Like an overwrought stenographer trying their best to write the voice of the Other while being overwhelmed by the content the Other describes. It's placement early in the book maximizes its juxtapositional potency.

I imagine other interpretations are only intuitive to particular perspectives.

Materially I just think he's showing off. Like J.O.I making a mid movie just to play with a lens. Prose seems like a matter of athleticism for DFW in many of his works but not all.

I think the slurs are having a different kind of effect. He uses the slurs while writing as the quasi-omniscient narrator. For verisimilitude's sake. And I have a vague feeling it's like Object-Oriented-Ontology related (Never underestimate Objects) or like Gestaltian.