Many theorize that the differences heard with changing VTA on the fly are due to minute changes in VTF caused by raising and lowering of the pivot point and not due to fractions of a degree changes in the stylus angle. I don't know what is the correct answer and I am not overly sensitive to this so I don't spend a lot of time changing VTA once I find a good spot. I do, however, attempt to find the correct VTA change to make with LPs of different thicknesses but only in a general way. Not for each and every LP. If changing VTA for every LP works for you, go for it. If you try it and don't find it making much difference, don't sweat it. That's my opinion.