On the one hand, if they're independent enough to actually want autonomy if we freed them, chances are DP wouldn't write it so that we're essentially just flushing that money down the drain, but chances are they would have other interests than just being identify monkeys like Maelor and Glyra are... and those two do it because one is living the high life and the work is actually moderately interesting--and even he needs to get out of the damn house before he goes crazy--and the other is bound by pact to do as she is bid.
Now, if you made them a wizard's familiar, they would probably be obligated to fulfill their master's requests regardless, which could happen to be identifying items. Or rather, it would make their time allocation more focused on that above any other distraction.
Of course there's also a moderate chance of them wanting nothing to do with smelly humans/dragons, but I mean... I doubt it? More likely they wouldn't even have a concept of freedom. Telling someone you're free when they don't even have a frame of reference of what that even means... just ask the Unsullied of Astapor. They'll sum up how they feel about that particular notion pretty well.
"Freedom?"