...would you put your best cord before or after the power strip?
Usually the thought is to use the better cord going from the wall to the power strip since all components will benefit from it. As you seem to realize, results vary and could be different for you.
As I upgrade power cords, is it worth doing anything with the short runs without replacing the long run first?
Perhaps. However, I would strongly recommend avoiding purchasing 1M power cords as a rule. They are hard to sell and many power cord designers recommend at least a 5ft run for best sound.
Usually the thought is to use the better cord going from the wall to the power strip since all components will benefit from it. As you seem to realize, results vary and could be different for you.
As I upgrade power cords, is it worth doing anything with the short runs without replacing the long run first?
Perhaps. However, I would strongly recommend avoiding purchasing 1M power cords as a rule. They are hard to sell and many power cord designers recommend at least a 5ft run for best sound.