Tzh21y
I have looked at a pic of the arm. Does the wire at the top of the arm come out of a hole directly above the pivot? Or is it offset? It is hard to see exactly.
If it is offset, then it will affect the arm in some way as it appears to be quite substantial. The fact that they say it can be used as antiskate would suggest this, as well as the fact it is able to maintain a loop.
I designed a couple of arms many years ago with similar arrangements in order to try and avoid the complication and expense of other solutions, and found that it was difficult to avoid some effect from the wire even though it was much finer than that of the VPI. It was not just on the lateral plane, affecting imaging and solidity, especially in the centre and towards the inner grooves, but also in terms of downforce variations which led to a generally imprecise quality, an uneasiness or edginess.
Those designs were rejected in favour of wiring that went through the bearings to give the minimum torque.
Recently, a friend of mine used some original old bits from one of the arms, a unipivot, and also found that the wiring was problematic. He started off by having the wire exit from the armtube, as in this pic,
Fernando's 1st version
and eventually ended up by running to the centre of the bearing housing and then straight up for a distance before looping it round the wire support.
The wire he used was very soft, but still not as fine as the original wire I used.
So maybe you could try routing the wire so that its axis of rotation is directly above the point of rotation of the arm. This will reduce the lateral torque, but the wire will still be prone to affecting the vertical movement. as it acts at a distance from the actual pivot point.
Using a longer arm will reduce any effects, as will higher VTF, so cartridges play a part, or using an "inner groove friendly" alignment.
I'll say nothing here about anti skate, as it is a contentious subject.
Hope this is of use or interest.
John