The single thing that is most different in reading protocols, as far as I can tell, between 'literary fiction' and SF/F, is that in the former genre a lot of language is metaphorical or symbolic which in SF/F is entirely literal. IIRC, there is one symbolic image in the entirety of Engine Summer, centered around an entirely ordinary object (the fly in amber). The rest is to be taken completely literally. SF/F protocols are the ones I grew up on, so it's hard for me to tell how much a person who is used to litfic would want to read the book as using symbolic or allegorical language. But basically there isn't any allegory or symbolism there. It's naturalistic writing about unusual signifiers, as opposed to rhetoric-filled writing about everyday signifiers.

I would love to throw somebody who is more used to litfic at, say, M. John Harrison, who pulls off the neat trick of having the things he writes about be their own literary symbols, so that a character of his can both literally be the Sophia, the incarnation of all wisdom in the universe, and the allegorical representation of that symbol in the thematic space of the novel. But with half of Harrison I don't even know whether he'd read as being in English to someone who hasn't read a whole lot of SF, because part of what he's doing is turning the literalized metaphors that have been the furnishings of the genre since its inception back into metaphors, and one might have to know the furnishings he's working with. Or might not, I don't know, I don't know anyone who's tried.