@Moth we don't know what the story is so all he will ever do from now will be ass pulls though.
He read the story of the MC of the novel, so he won't know everything UNLESS that novel is like pack fudged with Point of view stories making the novel a huge ass book detailing every thing that happens WITHOUT THE MC.
IMO his power isn't because he is a "reader" but because of those luxurious status screen like skills and mysterious "fourth wall skills" that looks like crutches.... NAY!, Automated wheel chair.
A reader would use his knowledge of the novel world to his advantage... unfortunately we have this isekai like system instead.
This story is still enjoyable though NGL.