I started using both positive and negative versions of the von Pohl scale back in 2002 when I found lots of earth energies had a helpful effect on humans. The Baron's scale was designed for geopathic energies alone, so I used -1 to -16 for geopathics and +1 to +16 for beneficials.
I think that part of the reason for the relativity and subjectivity of the scales is simply that we aren't all asking the same questions about the same energy, or the same part of a particular energy. For instance, if I check the intensity of the parallel, vertical planes above an underground water pathway it won't be the same as the intensity of the interlocking vertical cylinders within the same pathway. And the intensity differs from daytime to night. I also look at how the energy affects each of the energy fields surrounding a human and, if I look at all 56 layers, some will be more affected by a particular earth energy than others, causing differing symptoms if the energy is geopathic. I've even run into a few energies that switch from harmful to beneficial at dawn or dusk, and there are a few energies that have both harmful and beneficial components.
For those uninterested in the details, just finding out roughly how harmful something is at the moment may be enough. But I'm collecting as much data as possible in order to eventually tease out some further hypotheses to test. It's fun to show someone where the radial energy lines heading toward a sinkhole get increasingly close, and then show them the sunken ground above the physical sinkhole to which the radial lines pointed. Half of what I do is health improvement, the other half prediction and proof. It's all good!
"Develop an infallible technique, then place yourself at the mercy of inspiration." (from a craftsman, but it applies widely)