@holmz I am not familiar with the SOTA Bearing but in general the designs are to have a few sacrificial parts incorporated in the Housing.
The Housing Liner Bushes are Sacrificial, and the Ball at the Base or Sometimes Head of the Spindle are Sacrificial.
A Ball can also be found to be an Interference Fit which is embedded into the spindle and will be seen as a Half Ball when witnessed.
Bush Liners are able to be produced from a material of choice to the tightest of tolerance to match the spindle that is in hand, this is very beneficial.
There are numerous considerations for the material that can be selected for the replacement of a ball, I lean toward the lowest 'coefficient of friction' at this interface, but this can result in using a fragile material.
It is working with these components in the Bearings Assembly that usually produces an overhaul.
The Spindle is commonly found to be produced with a Case Hardening and will have to be subjected to substantial period of use in an unwanted environment to show abrasive damage or at the worst a measurable wear.
The Sump of the Bearing Housing can be prone to leach lubricant, measures are usually adopted to improve on the seal at this point, as having options on Lubricant Type can be beneficial.
Options on Viscosity of Lubricant from High to Low Viscosities are not a bad place to be. It is not uncommon to see where individuals have reported on the merits of a particular viscosity being in use.
If the Bearing assembly was optimised the impact on the replay is substantial, the Styli in the Groove will be in its best environment with an optimised spindle rotation and low mechanical energy transfer resulting.
Add P'holz to add to the management of energy transfer, well I wish I present to see your expression at the first Album Reply with the new designs in use.