[quote=@FacePunch]
I'm gonna get to work on a Thunderbolt/Boom post.

[@Dedonus] Where would the heroes most likely find these notes from Iron Knight? Does he know their secret identities?
[/quote]

Iron Knight does not.  However, his assistant Minerva, who is secretly Athena disguised as a human, went to Helios so that she could find them.  Therefore, they would find it wherever they are most likely to see it.