Already checked, I even contacted Pete Melvin and Fischer for their feedback.
Missed to paste this:


The WP indicated that the rules already refer to the hull centreplane, which indirectly requires the hull to be symmetric. The WP was not aware of any F18 designs with assymetric hulls. For clarity of the rules and definitions it was proposed to add:
D.2.x Only the parts of the hull under the waterline must be symmetric.
Agreed unanimously
This allowed a clear definition of the hull centreplane, allowing a new rule governing the restriction of inward-canting hulls, and thus boards:
X.x.x Hulls and their appendages may be canted outwards at the keel. Canting the hulls and their appendages inwards at the keel is prohibited, except where this is caused by curvature in the front beam as per rule D.4.2.
The maximum boat beam shall be 2.60 m with hull appendages in completely down position.