All of which makes me think that your quest for low wow and flutter may not uncover the most cost effective improvements. After all, the purpose of a turntable is to allow a stylus to accurately track a microgroove, let's say down to a micron or so.
To me, you may find it more productive to examine the tone-arm end.
It is a bit like Formula 1 racing. You can improve engine power, braking performance and / or cornering ability. After almost 100 years of focusing on power, computer simulations showed that the same percentage improvements in cornering force could dramatically improve track lap times. The simplest way is to increase downforce, even if doing so 'wastes' some power.
Being Formula 1, anything that was too effective got banned. We no longer see huge wings pressing down directly on the rear axle, nor side skirts which skid on the tarmac to create a partial vacuum, nor fans to suck the car to the track. But we do have aerodynamics which theoretically would allow a race car to fly upside down at 100-mph. At high speed, downforce can be triple or more the car's mass.
So I think trackability is nowadays more important than speed stability. In particular, how are unwanted vibrations channeled away from the stylus / record interface?

