I dont know if your being passive aggresive or actually talking a valid point, the internet makes it difficult to interpret sometimes.
Your response leads me? lost. I dont think I dis-agree with any of your findings but I dont understand the highlighted sections re-affirming your view which does not appear to be different from mine.
Relax, we agree. The highlighting was to emphasize the words in the sentence. My view is not different from yours. I was, however, making a point that you did not and which is often not appreciated when speaking of discernible differences. Many differences are discernible but are not, in practical situations, meaningful. That is, it's not so much whether we
can discern the differences but, when we can, whether they are substantial and, whether, once discerned, there is any preference for one over another. This turns out to be an important consideration in all sorts of comparisons.
This is what I think has happened to the OP.
I cut, fit and set up all DB bridges *completely* before taking them off and installing the adjusters. This means I hear each bass with the solid maple bridge in place and then the same bridge with very light aluminium adjusters installed.
In every case, the sound of the bass improves with the addition of adjusters. Its a subtle thing but there's an openness afterwards, a little more air in the tone, that makes the bass nicer to play and to listen to.
This is about as good as the evidence is likely to get in the practical world! That is, a discerning pro who has made multiple "before and after" comparisons.
+1 It makes sense to me!
There are many things we "mere humans" can't perceive: Elephant communications and whale songs, not to mention most of the light spectrum.
Actually, our eyes, by definition, perceive
all of the "light spectrum," which is that portion of the electromagnetic spectrum that's visible. The auditory apparatus transduces none of the electromagnetic spectrum and that's the sense we were discussing.

Furthermore, I wasn't speaking of absolute detection. We were talking about potential differences in the sound that could be the result of the addition of adjusters and how the physical materials employed could alter the sound. Basically, the changes are spectral in nature. That is, the "frequency response" is altered. I was pointing out that the spectral changes that "mere humans" can discern are likely far smaller than you might imagine. The ear and brain form one heck of a sensitive instrument.