This effect is more noticeable on the neck pickup because the string vibrates more toward the center of the string and a strong magnetic field will have more leverage in the neck position than in the bridge position.
Here is an experiment you can do that will be very educational. Assuming that the string width at the neck position is 1.875 inches wide. Mount 7 0.25 inch diameter magnets such that each string is located in the middle space between magnets and the pull should be less but may also have a different harmonic structure as any horizontal movement will induce a voltage each time it passes the magnetic field side to side. This should emphasize a higher harmonic component.
Tinkering is very educational and sometimes provides some unplanned results.
I hope this helps.
Joseph J. Rogowski