I'm not sure if the op fully understands the mechanism of the "Dimensional adjustment" feature. What is actually happening is that an increase of 0.1 actually stretches the shape by 10%. So, in a shape with three holes equally spaced across the direction in which the increase is made, the centre hole would have one side "stretched" in one direction and the other side "stretched"in the other direction...however the outer holes would have both sides "stretched" in the same direction, but by very slightly different amounts.
If a change is to be made to the function, exactly how should the adjustment affect the above described shape? Add a bit to each outer edge? Stretch the solid areas between the holes only? Anything other than a simple stretch raises a multitude of additional issues!!
I can only assume the feature was added to allow a simple "fudge" to a shape dimension to adjust for individual printer differences.....and not as a serious attempt to make design changes.