I looked at the definition and here it is (emphasis mine)

A steel man argument (or steelmanning) is the opposite of a straw man argument. Steelmanning is the practice of addressing the strongest form of "the other person's argument [(the steel man argument)], even if it's not the one they presented".

So yes, in that sense it is a strawman - you are presenting an argument that the other person would not make. For instance Eliezer asked Lex to kind of steelman believing in god I think. Now this can quickly go astray if one then says something like that believing in god can give somebody social advantage and that is why you should believe it - you are presenting an argument that the other side that truly believes in god would never actually make.