The relationship between VTA and VTF

What a can of worms....I experimented with my Graham 1.5's VTA dial and found that I could get a change of ~0.1g VTF with ½ turn of the VTA vernier. So when I reduce the arm height of the Graham - or put on a thicker record - I'm increasing the VTF.

This increase in VTF as pivot point lowers in relation to the stylus contact point is apparently a trait of 'stable balance' arms (MF mentions this about the Graham 2.2 in his Phantom review. Apparently the 'neutral balance' of the Phantom avoids this.). I just didn't think it would be this significant.

I.E if I have the VTF adjusted for best sound with a 120g record - putting on a 200g (which raises the stylus height relative to the pivot) increases VTF. Raising the arm pillar height restores the relative stylus to pivot height and hence the VTF.

Upon reflection the actual change in angle of the stylus (which is extremely slight) might not have much to do with the change in sound - the change/restoration in VTF is probably what I'm hearing.

Can anyone else with a Graham confirm this?

System Details
I'm not sure what a "stable balance" arm is as opposed to a "neutral balance" arm. I think that virtually all pivoted arms will exhibit this trait-I know mine does. You can drive yourself crazy with this stuff if you let it. I don't have any VTA on the fly capability so I simply adjust VTF to be at the high end of the range I want with thicker pressings knowing I'll have a little less VTF with normal records.

I would be curious about the "neutral balance" of the Phantom though and whether or not it really eliminates this if anyone can elaborate.
The Graham 1.5 has a balance CG below the pivot bearing. If you look at the arm like a sideways "L" (------i)then perfect balance happens when the arm is level, the bottom of the i is heavier then the dot in the stable config. Any up or down change from level (gravity) will have an impact on tracking force +,-. If the back of the arm is low and set for a thin record playing a thick record would increase VTF and of course change VTA a bit. The greater the config from level the greater the change would be. I set my VTA by ear then reset the VTF at that record height using a stand for my gauge then set VTA again. So far for me the VTA has a greater impact on sound that changing the VTF from recommended value. My arm is about level and VTF changes are, .o6 grams or so. I am a set it and forget it type of user so I will set it for the best compromise and leave it. I have regular records (120 gr?), 180gr and some 200gr. Looks like if I had a record in the 150-160gr range that would do me.

I image "stable vs neutral balance" impacts other parameters as any up or down or sideways movement is now a bit different because of the CG change.