Dear @intactaudio : want to give you an example of two Löfgren A calculations where even that the EL of the tonearms is different an even that in both the overhag ( obviously ) is different the null points in both tonearms have the same value ( you can check in any net calculator by your self . IEC standard. EL/overhang are two of the parameters you mentioned in your posts:
EL 250mm.: overhang 16.5mm. null points: 66mm and 120.89mm.
EL 305mm: overhang 13.37mm same null points.
Obviously that the off-set angle is different too in both tonearms.
R.