Staff special firing mode

[Akatosh's Pug]

So, I've read some stuff on the wiki about the Staff of Magnus, including the part about this "alternative" firing animation.
Essentially, when I fire the staff and then very briefly stop and continue to fire again, the character does some king of staff waving animation, while the target point moves around (can't shoot straight where I want).
It seems like the most useless mechanic ever, cause all it does is waste staff charges while I struggle to hit something.

Does it have any practical use, or is it just something left unfinished by the developers?