Nope, Dan's Belief is if Mira realized our MC is the Hero, then she would be disappointed and think he is lame.
Yeah, this is the really incredible turn that made me understand why Dan is in this thing. He figured out that Clark Kent is Superman, and thinks that if he's able to show that the guy people look up to is actually always rushing off somewhere or avoiding people when there's trouble, they'll think less of Superman.
Except... everyone else will immediately realize that Clark is always off somewhere else when there's trouble because, you know, he had to go turn into Superman. Dan's able to be an antagonist because he is
so stupid that he thinks exposing who the hero is will make people dislike the hero. It's allowing him to have figured out the secret, take actions to expose it, but maintain an antagonistic relationship.