Ornatus-Mundi[Zenith]
7136
I think it is NOT a requirement...
there was a discussion some years ago here on Purists about this very topic:
Furthermore, when you read the requirements of the Poinçon de Genève there is nothing mentioned about the column wheel. This might have changed due to recent revision of the requirement.
I will provide more information in a few weeks (months??? Oh my scarce free time...).
Best,
Magnus