Imagine the times that Johnson would have put up if he had not been caught. He was so far ahead of his time!
Actually a lot has been postulated regarding that. I am not sure what he was ultimately capable of, and we will never know, however, I do agree with you that he was very far ahead of his time.
An interesting thing about Big Ben as he was called, was his start. Well it worked like crazy for him, but was not orthodox in so far as technique was concerned. Apparently it involved almost jumping with both feet off the blocks or something like that.
Anyways, huge numbers of sprinters the world over were apparently lost trying to emulate Ben's start style. That all ended after Seoul though. A good book about all that is Speed Trap by Charlie Francis, Ben's old coach.