OBVIOUSLY, I CAN speak only to the Silver- and Bronze-Age incarnations of Superman, so I can't really address your question.
I did want to point out that there was even a change in the effect of magic on the Man of Steel even back then. In the Silver Age, Superman was affected by magic; by the shank of the Bronze Age, he became vulnerable to it.
So, what's the difference, one might ask?
Simply, the Silver-Age Superman could be affected by a magical spell. For example, Mr. Mxyzptlk could turn his head into an exact image of Felix the Cat. But, if Mxyzptlk materialised a boulder over the Man of Steel's head, when it dropped, it would shatter against the Man of Steel's noggin---because, you know, he's invulnerable.
As the Young Turk writers took over in the Bronze Age, they neglected the subtle difference (as they neglected many other details about their characters' continuities). Suddenly, if Mxyzptlk dropped a boulder on Superman's toe, it would make him go "Ow--ow--OWWW!" because it's a magic boulder. And it would have to be dropped on his toe, because if it were dropped on his head under the new paradigm, it would kill him.
In short, now the Man of Steel was vulnerable to anything created by magic or had been influenced by magic. The 1960's Superman, if he'd had a mind to, could have punched Mr. Mxyzptlk out cold. But with the 1970's Superman, his fist would have just harmlessly bounced off Mxyzptlk because he's magic.