I do use the resonance calculator. I always check before installing a cartridge. I have a number of headshells and weights, so I can tailor the mass to obtain resonant frequencies between 10 and 7 Hz. That is, if I know the arm's effective mass. I understand that this is not the only item that needs proper arm/cartridge matching.
I won't quibble about the arm/cartridge matching. I do think that the cartridge contributes much more than the arm does. I don't have any data, just a "feeling".
I don't use the DP-57L much because I don't like the arm's looks. A silly reason, but that's the one I've got. Perhaps I should mount the Koetsu or Shelter on it and listen. The adjustment of arm height is a bit of a pain.