Ladegaard makes no mention of eccentricity. Warps do drive temporal variations in VTF and it makes sense to me that these would act with skating (or AS) to drive a sideways W&F. Just another flaw in the AS reality that isn't addressed in the theory.
He does discuss eccentricity, more than once. Figure 18 on page 7 labels the 0.5 and 1.2 Hz lines as record centring and ellipticity, and the text beside Figure 22 on page 9 says the spectrum below 10 Hz is totally influenced by the eccentricity and irregularities of the test record, fundamental about 0.55 Hz, with the 10th to 13th harmonics at high level. It is the dominant subsonic content in both his flutter and his rumble spectra.
The skating coupling you describe is real, but it’s the minor one. Warps modulate VTF, skating force rises and falls with it, and the arm moves sideways against the cantilever. The along-groove share of that goes through the offset angle like the direct path. The same VTF swing also drives the VTA path, and that one is larger by tan(VTA) over μ·sin²(offset), somewhere between five and ten times for a 20 degree VTA and a 23 degree offset, depending on the friction coefficient. Whatever the exact figure, the skating route is a fraction of the one he actually drew.
It isn’t unaddressed, either. Skating force is friction, which scales with VTF, times the sine of the angle between the groove tangent and the pivot line, which on an aligned arm is about the offset angle. A VTF that swings with warps gives a skating force that swings with warps; that follows directly. That a fixed anti-skate can only match the average is the standard compromise, not a hidden flaw.
Skating and anti-skate don’t appear anywhere in the paper. So that coupling is your mechanism, not his, and it isn’t what his offset remark was about. It’s fine as a hypothesis, but you brought the paper in as the authority for warps driving the offset path, and he never makes that connection.
