Well I’m not trying to recreate a render so don’t misunderstand me, I’m trying to set a good starting point for further adjustments to the render. So I strongly disagree with the statement “it’s a pointless endeavor”, I would even go as far as to say that: “when you take something apart then you should be able to put it back together again”.
My goal is very simple, I want to be able to adjust (color correct, blur, etc…) individual passes without changing anything else. To do this I need to be able to separate the render in individual passes and adjust only the passes I want to adjust and nothing else. At this point simply compositing the individual passes back together again will automatically result in a different looking render, so its impossible to have full control over what you change because basically everything will change.
But of course if it cant be done it cant be done, I hope that this is a point of improvement that would be considered by the Blender developers in the near future.