The study with regard to the random teleportation magic formations appeared at the end of the book.
Essentially the limitations and ranges of the random teleportation formations, and their usual or unusual characteristics.
Also, that it is highly unlikely to wind up being teleported into the middle of something, like the ground or a wall- even if it is inside a cave.
If it's the case with Animas, it's because the magical power of the metastasis ahead and the magic of the thing itself doing the metastasis repel each other, this may be related to the concept of not being able to materialize an attack magic directly inside the body of a person.