I suspect that the mention of Lenz's Law with respect to back EMF may be a bit misplaced here. The simple story of back EMF when it comes to a speaker is the inertia forces the cone to continue to move after the signal tells it to 'stop and go the other way'. This 'undriven motion' will generate an additional voltage which will then appear at the amplifier. Lenz comes into play here when the low output impedance of the amplifier appears as a near short allowing a 'large' current to be generated which following lenz will create an opposing current which acts as a 'brake' of sorts.
The Key difference between back EMF in a driver and a cartridge is the speaker is electrically driven to create a mechanical sound and the cartridge is mechanically driven to create an electrical signal. In a driver inertia causes an additional mechanical movement that is electrically 'damped' by Lenz. Unlike the speaker where the heavy lifting is done by the electrical signal, the cartridge has the groove as the guiding force. A lateral cut groove drives the diamond left and right and an important difference is after a peak in the left direction the groove wall forces the tip back in the other direction and the inertia causes instantaneous pressure on one wall to increase as the pressure of the opposite wall decreases. There is inertia but no real 'overshoot' to invoke Lenz like in the case of a speaker.
When you look at a stereo cut where there is a vertical component in addition to the lateral things change. On the downhill path to a valley a similar thing happens to the lateral situation. The tip hits the low point and reverses direction up momentarily increasing the downforce. It is when it reaches the following peak where I see inertia coming into play since there is nothing beyond gravity to push things back down to the next valley. After the peak, inertia will keep the tip going in the same direction resulting in the situation where downforce approaches (or reaches) 0. If you look above at the screen grab I posted from CBS STR112 it states that the dynamic groove wall force can vary from 2x the static force to nearly 0. The simple solution to mistracking is to add VTF until you are kept a 'safe distance' from 0. I think it is generally accepted that too much tracking force leads to record and diamond wear and too little force leads to mistracking so it is the 'approaching 0' aspect that needs to be looked at. It is my belief that Loading can effect the behavior on the vertical uphill peaks causing a dynamic brake if you will which results in better dynamic tracking ability.
An interesting test of this on my list of things to try is to compare the results of loading with stereo vs. mono records. For what I say above to hold water, I would expect the results of loading a stereo record to be greater than that of a mono record due to the addition of the vertical component. I should get time to try this experiment around 2024 :-)
dave