While I agree that VTF and VTA are interrelated, as a pratical matter this need not be anything to consider on a day to day basis, if during initial set up you pick the mid range of the cartridge manufacturers recommendations for VTF and then set your initial VTA for the thickness of LP's you use the most. Once you have done this, then you can further fine tune the VTF and then the VTA by ear for that thickness of LP, and thereafter only the VTA for record thickness.
I can't imagine that anyone without dog's hearing could hear a difference in VTF caused by VTA changes for different record thicknesses. The obverse would not be ture at all.
Although its going to be considered a heresy on this forum, you can make minor VTA changes when you're lazy, by merely rotating the counter weight on your arm, assuming that it has settings marked so you can return it to its original settings after your done. This works especially well for those without the ability to do VTA on the fly. The key word here though is "minor".
