How to remove the spellcaster trait from townies?

"MidnightAura;c-17292651" wrote:

"Tistou;c-17292635" wrote:
WHAT! The service sims can start using magic? Wow, I guess this won't be my next pack to get.

Anyone that your sim hasn’t met is eligible to become a spellcaster for performance reasons.

As in careless and lazy programming. Not having any sims be spell casters (other than sages and bona-fide realm residents) would be even less of a performance drain. Same old excuse that's been trotted out for years, and getting more than old.