What is the relationship of Iain Banks's The Wasp Factory to science fiction? Do you have articles about The Wasp Factory as science fiction?

In the Guardian article whose link is below, Iain Banks speaks about his origins as a science fiction writer. After receiving multiple rejection slips from publishers, Banks decided to shift to writing mainstream fiction with The Wasp Factory. However, as he explains in the article, he did not totally abandon writing science fiction. Instead, as he says in the Guardian article from July 11, 2008 (link below), he decided to abandon the large canvas of the science fiction writer and use "a more restricted palette and to produc[e] what felt like a miniature in comparison." In other words, he still used science fiction techniques and themes in The Wasp Factory, but instead of using other planets in his story, "the island [on which the story takes place] could be envisaged as a planet, and Frank, the protagonist, almost as an alien." In this way, Banks could still, in his words, "treat my story as something resembling SF [science fiction]."
In other words, Banks wrote about what was alien on our planet in The Wasp Factory rather than using aliens from other planets, and he used elements of science fiction in his story. For example, Frank's discovery that he is really a girl is part of the author's examination of the constructed nature of gender identity. Frank's father, Angus, has been trying to turn Frank into a male through the use of drugs, and this part of the novel includes elements of science and science fiction. 
https://www.theguardian.com/books/2008/jul/12/saturdayreviewsfeatres.guardianreview5