I have an old Bear spinner wheel balancing Machine, It has a couple sets of mounting plates with multiple holes for different wheel patterns. When you can't match up the bolt holes there are a couple cones with a one inch bore used to mount a brake rotor or hub, Static balance is easy. To spinn balance a rotor I would have to change out the steel driver wheel that contacts the tire . I have seen quite a few rotors with large Roll pins pressed into the cooling fin holes. Just like drive shafts I don't like using one that has a lot of balance weights.