Tonearm mount on the plinth or on Pillar ?

You said that was correct....
You then contradict yourself by writing:-

The result is it is quite impervious to the volume level in the room; even at 110 db the sound is still very relaxed.

The two statements are logically incompatible.
No amount of plinth dampening will avoid the effects of air-borne sound waves on the vinyl, cartridge, stylus and tonearm.
The fact that you and many others can listen to vinyl played back at excessive volumes demonstrates conclusively that air-borne sound waves have no effects on the turntable system.

Actually I'm not contradicting myself at all- merely point out that the design is successful. I assume from your post here that you did not actually read the post from which you quoted or such would have been rather obvious.

I've been digging through this to the point of multiple circular thinking all leading to nowhere. My comprehension, while not fully through, does lead me to question many of the tenants expressed here, if only due to being invested in a TT/plinth?/tonearm which violates almost every principle presented here for superior SQ. 
Trans-Fi Terminator tonearms , linear tracker with air bearing. Salvation TT with magnetic bearing, floating for all practical purposes. Resomat platter pad which further isolated the LP from the platter. nothing is connected with respect to vibrations being transmitted concurrently during playback. Sounds great. 
I did follow Terry9 and place a little damping material  on the arm wand to some good effect. 
Maybe it's my tin ears but it sounds really great to me.

Dear Halcro, You wrote, "The fact that you and many others can listen to vinyl played back at excessive volumes demonstrates conclusively that air-borne sound waves have no effects on the turntable system."  But that is an incorrect assumption based on all my past experience.  I have been present many times, in many different listening venues, when acoustic feedback causing distortion was sound-pressure-dependent.  Backing off the volume control could reduce the effect and eventually eliminate it entirely, in these instances. Perhaps this is not a problem in your house, but it is a real phenomenon in some others. In the case that Atma-sphere (Ralph) describes, perhaps conditions were such that there was no appreciable acoustic feedback, even at 100+ db. It's possible.  Careful set-up and room damping can indeed eliminate or remove the problem, but that does not mean it does not exist.

Dentdog, More to the point, is your Terminator tonearm mounted on your Salvation turntable or is it on an outboard arm pod, separate from the turntable?  The Resomat is indeed a contrarian design in that it specifically decouples the LP from the platter, whereas most platter mats make an attempt at coupling to facilitate the dissipation of spurious energy delivered into the vinyl by the passage of the stylus in the groove.  Many do say the Resomat works great, however.  Which should make us re-examine the theory of the platter mat.

Lewm, the Terminator tonearm actually pivots vertically on two contact points of an underslung carriage. This is joined to a sliding metal inverted V bearing which slides horizontally on a similar inverted arm,separated by a thin cushion of air. A pump with very low pressure allows for a long thin surface, decoupled by air. Thus the arm can pivot vertically while the sliding inverted bearing moves without resistance, [air cushion]. The support arm under the inverted bearing is attached to the plinth, with the air cushion separating the bearing from the support arm. The air cushion completely separates the inverted bearing and the undercarriage from the support arm and the plinth.
As to the resomat, I have experimented with three other mats and in each case the dynamics I was accustomed to hearing were sucked out of the music.This was without doubt the most dramatic negative change I have heard in the system. The music just died. Needless to say the resomat is in place permanently.
While I have formally studied physics on a basic level and have some limited understanding of airborne/foundational vibrations, in no way am I qualified to refute or support either of the theories being bandied about here. I do know however that the above methods put into effect, including the magnetic bearing supporting the platter all work to decouple all the working parts. This to me seems to reduce the chances of resonant/non-resonant vibrations being transported throughout the playback system. Totally contrarian I realize, but it works and to me it works better than what I have heard otherwise, particularly in the case of high db playback.
My ego isn't really attached to this, so anyone who wishes to shoot it down, have at it.