I'm sure this is out in the ether but I haven't seen it remarked: Iran is the big loser in the Trump Kim summit. If NK shuts down their nuclear program, it sets back Iran by decades. The Persians do not have the technical smarts that the Norks have.
Not to mention the diplomatic pressure. If Trump is able, willing, and successful convincing the KJU that he would should give up his nukes “or else” puts actual fear into the Iranians heads.