Pretty sure that will make three fifths of **** all difference. Definately not the equivalent of a 2mm thicker bar. Its the distance from the pivot point that'll determine how much force is needed to twist he bar enough to start trying to lift the opposite side. The shape the bar takes to the endlink has marginal impact on the torque required and will be the same for any of the three holes anyway. So by going up and to the centre the true distance to the pivot point will be barely any different to the stiffest original hole, as in probably half the distance change you get between the stock two holes. If you'd gone straight up from the closest hole you might have had some more difference but bugger all where it currently is.
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