Jag tror inte att det är förbjudet, men av en eller annan anledning tror jag inte att Quentin gör mycket magi i paus (det talar i alla fall inte om att han praktiserar stavar).
I kapitlet Alice in The Magicians
when Julia finds him in Chesterton and demonstrates Ugarte'S Prismatic Spray for him it says he does "a quick counterspell to snuff out the Prismatic Spray." So, he at least did that much, and it doesn't say he was ever reprimanded for it.
Och när Quentin går hem med Alice under en paus står det
After the first week, they'd finished all their homework and were free to lie around and goof off.
Jag skulle anta att de skulle behöva göra lite magi i läxor.