It is a misnomer to say that the lines seen on a business strike coin is caused by Die Polishing when they are in fact caused by Die Cleaning. Coin dies are polished to remove scratches in the surface of a die in order to produce a proof-like coin. It is a very skilled and time consuming process. Die Cleaning is an action done to the dies while they are in service to remove debris so the dies can produce a better looking and exceptable business strike coin. This is a very aggressive action that uses course grit sanding that can and does leave lines scratched into the dies. These scratch line are tranfered to the coins. This cleaning action also can change the depth or relief of the die. Photo of a 1943 LWC
You forgot to mention that coin dies are ground and polished to remove clash marks from dies. Just cleaning will not remove severe die clash marks unless you want to call everything cleaning. then polishing and grinding would be included in the cleaning process.
