Tonearm mount to the plinth vs arm board vs rotating arm board vs isolated tower

Dear @kanchi647 : 1+  with millercarbon advise.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

For practical reason this type of Steve Dobbins plinth for Garrard 301 is universal for different tonearms if you're going to use many.
Same construction in Stereophile article

Aesthetically Artisan Fidelity 301 is the best (imo), but you need many armboard to swap tonearms.

Well, I know Steve Dobbins. I have met him face to face and have had extended conversations with him about optimization of the venerable Garrard 301. Steve will tell you that the swiveling arm board is a compromise and is not optimum. It is a useful convenience feature. A very useful and very convenient feature but still a compromise. For optimum performance, he advocates mounting the tonearm directly to the plinth. No replaceable cut-outs, no extensions, fixed or rotating. Why should this be surprising when extensions resemble diving boards?
Everything needs to be kept in perspective. The Garrard 301 is not the ultimate in terms of being quiet or in terms of speed accuracy. Instead, it has it's own sound, a very good one. In light of that, one should not sweat bullets about having or eschewing a rotating arm board. They are clever and indispensable for those that want to use lots of different arms. The compromise in overall SQ is likely negligible. I would argue that it is only when using the very finest MC cartridges with the 301/401 that one should avoid any otherwise avoidable compromises. 

Steve will tell you that the swiveling arm board is a compromise and is not optimum. It is a useful convenience feature. A very useful and very convenient feature but still a compromise. For optimum performance, he advocates mounting the tonearm directly to the plinth. No replaceable cut-outs, no extensions, fixed or rotating

For Garrard or for Direct Drive too ? 
Such plinth is easy to made if we already have one tonearm to mount. 

We were discussing the Garrard 301 at the Axpona 2019 room featuring his turntable, a 301 on a Dobbins plinth with a Reed arm and a top of the line VdH cartridge and Magico speakers. I don't recall the electronics in that room. The room sponsor was Van den Hul's former distributor who has since then been replaced with VPI. 
My opinion though, fwiw, would not change with any type of drive system.