This also has some interesting judicial applications. It might be practical to train all judges to sense emotional Allomancy (like obligators used to be trained), but you certainly couldn't train jurors to do that. So that might be a big obstacle to Scadrial developing the jury system.
P.S. To anticipate a possible objection, you couldn't spot them with bronze. Without a general knowledge of Hemalurgy, there's no double bronzes, and that means nobody who can pierce copperclouds. All you'd need would be a Smoker confederate for your hypothetical Soother.