Cometic rear main seal vs...

WHAT?
You do know that you have to polish the crank to use a rubber seal. I have never had one leak if installed correctly.
That is something I would like to know - if I use this rubber seal, do I have to remove all the cross hatching on the crank that is there for the old rope seal? Does it have to be polished shiny in that area for the seal to work? I would assume it does. But then, to remove all that crosshatch, wouldn't it reduce the diameter of the seal surface and reduce the efficiency of the seal?

Thanks