I always check this box, even if I don't see any noticeable chatter, just to make sure.
Is there ever a reason or time when you shouldn't use "Reduce Chatter" in Key Cleaner? Why is it defaulted to unchecked?
It also softens the key so in effect removes information that could be useful for things like fine hair.
Every key is different (even from the same shoot) so to do film quality keys you need to consider each shot on its own.