Mijo, you are very consistent in maintaining that a tonearm should have no sound of its own, but what does that mean? Since we can’t know how a TA sounds without a cartridge. And different TAs with different cartridges can sound very different.
Agreed. Or, to put it differently, saying that "a tonearm should have no sound of its own" is in logic terms a tautological contradiction. A tonearm can not be evaluated without a cartridge mounted and playing a record. You now have vibrations going from the record into and onto the cantilever and then into and onto the tonearm. Sympathetic resonances are impossible to eliminate entirely no matter the design, material, and damping.
Vinyl replay is the inverse of loudspeaker transducers. And like loudspeakers, you can go to heroic lengths to eliminate enclosure vibration but the drivers installed in that inert enclosure still vibrate and distort when driven and in the process of doing so the floor and room react to the vibrations as well. This is analogous to what is at play with cartridges and tonearms. You have to face reality and "play the room" by which I mean an ideal tonearm for a given cartridge compliments the cartridge in a euphonic manner.
To put it even more simply, we listen in homes, not laboratories.