@holmz This is one link I had forgotten I had bookmarked.
It contains images that will surely get the creative thoughts working overtime.
https://www.avsite.gr/forum/threads/dd-turntables.178381/
The Through Section of the JVC shows a substantial material has been selected for the Chassis and the walls and base of the Recessed Bowl.
The Bowls role is usually to house the Stator and additionally is used to support the mounting of the Platter Bearing Housing.
I have seen a selection of DD TT models that I have shown an interest in that has a wafer thin bowl wall material as a comparison to the JVC.
I have also informed a engineer friend who had one of the models with a very thin bowl material and the outcome of their investigations was that a flexion has been occurring and this energy is most likely to be received by the Cartridge.
The flexion will also show as an eccentric rotation and this a independent speed strobe will show the eccentric rotation will impact on Speed Stability.
The eccentric rotation will also impact on the stylus interface within the Groove and will most likely be a cause of a distortion.
Such conditions that are transferring energy to the Cart’ and impacting on the Cart’s Geometry when in the Groove, when present, will not enable a Hi End Tonearm and Cartridge to perform at their best.
The cost associated with such ancillaries and the compromised environment they are potentially being used in, will hopefully have been identified in advance by the user and have been accepted as an acceptable condition to continue with.
There are methods known for a recess bowl produced from a poor quality material, to make a recess bowl and bearing base rigidly secure and substantially decrease deflection, maybe even eradicate it.