Quite often we see material after it has been cut to the final flat shape as this means that any small scratches can be removed or minimised by the polishing process. This, of course, is only applicable if the polish removes any surface stock, unfortunately Bright and Mirror Polishing would not remove them.
However when working on the profile prior to polishing it’s best practise to keep damage such as scuffs and scratches to a minimum. The deeper the scratches the more the surface finish has to be reduced to get to the bottom of the scratch.
On thicker material there is of course more room for manoeuvre but on thinner sheet that has been scratched there are more likely to be instances when the damage can’t be removed without extensive (and expensive) additional work.