I don't really see the circlet as being all that imbalanced anyway. A wizard who uses it will eventually want an intelligence of 20. If they dump INT and put the stats elsewhere then they will never manage that. On the other hand, a wizard that is built as a fighter that uses wizard buffs can do that without 18 int. That wizard will also fall behind an actual fighter (at least as far as fightery things are concerned) once level 5 and 11 are available for multiattack. You can use the circlet to get 18 a bit quicker than you could otherwise, but if you are power focused you will probably buff int to 18 at level 4 so that you can raise it to 20 at level 8.
EK probably makes the best use of the circlet, but even there I don't think that 18 int really breaks the game relative to what other fighters can do.
In my play through I put in on my 8 int warlock to help with skill rolls. This was really nice, but again... hardly broken.
In any case, that item in no way breaks the game, even if you are trying really hard to break it. It does however very nicely justify the smart ogre with clever dialogue, so for that reason I hope it remains in the game.
