So, if these feats are an anime-only, why do we use them?
Simple reason, because the author sees the anime as a valid material for the story, and has also applauded the efforts of the producers in reading the source material, going as far as describing his interpretations as kind of inferior to them, despite the fact that the anime cuts down about 90% of the dialogues between characters, and only uses main hype scenes. However, anime is mainly used for promotion purposes, the same goes with the manga.
However, the author does show his presence where the story and events and discussions related to the anime production are done, and he is not someone who has major complaints, in fact, he even sees the story adaptation in the anime as a good one, to the best of its extent as it can go.
Syougo Kinugasa-sensei applauding the efforts of the anime production team and mentioning how he didn't have any problems with the script writing - a process which includes the topics of dialogues between characters with events coherent in them.
Illustrator Tomose Shunsaku-sensei and the author both reflect upon them even getting some ideas regarding characters designs and character personality (and at that, of the main character himself) and even implementing them (though this is not supportive towards the establishment of the canonicity, this is helpful in describing how much the creators of the novel themselves value the anime as not only a promoting medium for the novel, but also as a proper source of information).
SOURCE GOES HERE
Manga can obviously be used for stuff as well, due the author himself working upon it with a manga illustrator.
So, seeing this interview, and seeing the work in the anime, we should see feats as: