Not a bad idea to have, or to aim for learning but CNJ's have their own -emn spells that work better for how a mage needs to get rid of their spike enmity.

CNJ Action Level 38: Shroud of Saints
Temporarily reduces enmity by half, and gradually restores MP while effect is active.
Recast Time: 180sec. / Duration: 20sec. Exclusive
Keep in mind, I currently have Archer high enough rank for Chameleon but will loose it when patch happens. That being said, I only used it in the past a handful of times. Usually only when people are still learning a new fight. Once people know what to do, I never have hate or mp issues. At least with current in game content.

However Chameleon might be helpful to THM's. Kinda depends on the fight, and how traits will actually proc.