There are many undercover activities requiring sprezzatura performances.
Whether those activities involve working as an understudy or a politician or a musician will very much depend upon the context involved.
Undercover work, of all sorts, particularly involving intelligence, tends to require some sort of blocking.
What is your experience of uncover work?
Have you ever worked as an undercover journalist?
How do you tell when something or someone is genuine or a front?
How do you avoid detection, and avoid deception?