Changelings don't copy traits

[Frank_Stein]

I dunno. You could just make it look like the changeling has those traits when observed. Really though, while this trick exists, it's very conditional.

You gotta have a changeling, combined with someone that has the trait that lets then know traits at a glance, and either memorize other players traits or dig through medical records to compare them. Which really, if they're dedicated enough to actually use the medical records to oust a ling, I think they've earned it.