Mm.
So, are The Affront the literary equivalent of a human in a halloween costume? Extreme sadism as the only definiting trait I can recall, so they probably count as Planet of Hats* even if the physiology is too different to be a costume department's job in a TV show.
Sure, it's really hard to do SF where you have aliens and keep them alien, because they no longer fulfil ordinary plot parameters. The key characters in the parallel story in Greg Egan's novel "Incandescence" aren't humans, never have been humans, and they live somewhere that humans would immediately die horribly and we'd need an XKCD "What if?" discussion to figure out how they die exactly 'cos they're much too close to a collapsed star and there's also no Oxygen and you can bet everything is totally saturated in radiation... They're probably... tiny? Nevertheless, they're our protagonists for fully half of a novel, so, they're going to get humanized.