The ZS is just a characteristic curve. Leaving out extreme contractions, the ZS does not change the range of luminances the film records. It only compresses or expands contrast to make things easier to print (in theory at least). Just keep local contrast in mind, not only total contrast. Blindly applying ZS expansions and contractions to "fit" the paper is not always the right thing. Visualize the printing process as part of the total system when you are making the decision on how to expose and develop the film.