Jean Franco’s 1989 article by this title (Hispania 71.1 [March]: 42-48, available through JSTOR) may be worth revisiting. I always find Franco to be 50% grossly overgeneralizing and reading poorly, and 50% well informed and intuitive. That means that even if her texts are insufficient as endpoints, they are good starting points.
I am interested in that piece for purposes of contextualization. For purposes of interpretation I am interested in this post on the experience of reading Dambudzo Marechera – a writer unrelated, it would seem, yet in some ways uncannily similar to Vallejo. Also from the same author, and also for Vallejo related reasons, this post on Bataille and the postmodern is well worth noting.