@nanadric even though replies from myself are repetitive and prolix, they are are not offered with a intention to be viewed as coming from somebody who styling themselves with a usage of language that is grandiloquent.
As for the lexical content of the OP, you have stated the following, it by myself, is being viewed as a means to describe a condition you have witnessed, and one which has been created as the outcome of your experiment.
"My observation however is that also ''deviant'' cantilevers which
nobody would buy look STRAIGHT IN DE GROOVE. Ergo:: (using ergo with a replacement word, to assist with seeing the final statement being put )
Therefore :: it is the groove which determine cantilevet/stylus position .?"
The idea being proposed, to my interpretation, negates the notion, that there are interfaces between parts in the assembly that require critical attention to the setting up, which are required to ensure the cantilever>Styli is optimised in their position and the act as a constraint, ensuring the Cantilever is restricted to function within a operational envelope.
What the statement does seemingly attempt to suggest, is that if a Cantilever is noticeably out, as a sideways alignment, as a result of the Styli being placed in the the Groove, the observation of the return to a Centre position is a acceptable method to correct this condition. If all one wants, is to observe a centred cantilever, then this is for most with this as the interest is adequate.
In general the centred cantilever is not all one wants, there is the want for an overall correct function of the assembly that is designed and belonging to the model of Cart'.
The Groove being able to place the Cantilever as centred to the body, is not going to be enough for most with an interest in this as a functioning device, the outcome of your experiment will most likely not offer a reassurance a fix is in place.
The Styli being placed in the Groove, in my thoughts, is not going to be adequate to correct any other conditions present, that may be with fault, and the askew Cantilever is the indicator something is amiss elsewhere.
My advice to 'anybody' with an interest in a Cart' and who are expecting the Cart' to function to a standard that shares similarities with the Cart', at the time it was first put to use as a New Model. It will be best practice not to acquire a Cart' that has indicators present that suggest something is now quite different to how it appears as an unused design.
If one has other ideas for the Cart' and have a different intention beyond just experiencing it used as a tool to create a replay. A Cart' can then be considered in any condition it has been discovered to possess.