All good points. I am sure David has done much more work on this subject than I.
I would only comment that the etiology of "sibilance" is one of the most vexing among problems that occur in vinyl audio reproduction. (Meaning, there are many causes.) One of the last elements in the equation that I would indict is the tonearm, per se. VTA, VTF, azimuth adjustment, the cartridge, the LP, the phono stage, all would come ahead of some intrinsic deficiency of the tonearm design as a cause of sibilance, so long as we limit the discussion to really well designed and well built ones.