I don't think I've ever finished reading one of his books and felt... comfortable. I'm neither trans nor gender-nonconforming, and I found getting to know the character of Frank, and his father, and his brother, both generally upsetting and at times incredibly tough. It is a total surreal mind-fuck of a book (who said that originally?) but bearing that in mind, it is also an incredible piece of writing. And good enough that I've gone back to read it another twice.
I also put that he does not, in any book I've read, deliver any endorsement of male chauvinism. In fact, if you get to the end of The Wasp Factory, I'd say it was entirely the opposite.