This seemed always baffling if someone openly "confessed" suffering from the imposter syndrome.
It is like calling yourself a "skeptic" and taking joy in dismantling other people's beliefs, yet reacting with extreme sensitivity the moment your own convictions are touched upon. Or if you were really paranoid, you would be unsure of everything (even of your paranoid state) so you wouldn't just confidently drop that label in conversation doing so usually serves as a polite excuse for being a "control freak" which in turn serves as an excuse for something else and so on.
In a broader sense this touches upon a deeper cultural issues around appearances and self-identification. In (a lot of) different cultures one rarely talks about an internal state in an abstract, systematic almost clinical manner instead a wide breadth of colorful almost childlike language is used to describe rising and ebbing feelings while at the same time one's actions are observed very diligently and somehow quietly tallied over time.
Under those circumstances, you can bluff, obfuscate or outright lie and it matters very little so long as your actions are deemed good conversely if you present yourself as genuine, "authentic," and vulnerable while your actual deeds are horrible: out you go. So overall there is less "flexibility" and more "accountability".