I suppose Lee was in a situation much like Erwin Rommel was. Lee was certainly aware of the horrors of slavery. And Rommel was certainly aware of how the German Jews were being treated (kristallnacht, etc.)
Eventually, Rommel entered into a violent conspiracy against his government. Had the south won the war, would Lee have done the same?
Had the south won the war, would Lee have done the same?
I think he would have opposed it. Eventually it would have collapsed of its own dead weight. It was not cost effective and the Zeitgeist was against it.