Rating system / List updates

If it's possible, I think it would be more practical if we could change the rating we have given to a drama without it appearing again in the list updates as completed. For example, adding an option so that we can choose. It may sound useless but if you rewatch a drama/change your mind/add dramas you watched a long time ago, or want to completely change your rating system, you may not want to ruin your list updates.