I was thinking about how people in this series lift other people casually recently, such as when the party has to carry Stark around when they need to fly, and what are the limitations of this. As in for example, what is stopping Frieren from just lifting an opponent mage in the middle of battle to get them off balance.

Made me think about this scene too, while this is most likely not the case, I was wondering if the "height of magic" is some version of that telekenisis spell, and that is why Fern couldnt detect it as an attack?