There is some discussion about the cassettes. Some people see it as a valid loophole in the 'put in from the top' rule.
The cassette itself is not illegal. What is illegal that the daggerboard goes into the casette from the bottom. It does not make any difference if you put the daggerboard in through the bottom of the hull or the bottom of the cassette, which is a part of the hull.
The hull is the placeholder for the daggerboard, The cassette is a placeholder as well. It cannot make a difference if you look at a part of the hull or the complete hull. Else it would be legal as well to put a daggerboard in a separate hull and then you take the whole hull to assemble the boat.
The post is not meant to create any controversy or ban some sailors.
Apply the rules properly or skip the rules. Both options are fine.
At this moment it would be wise to keep the rules as they are. The class can add a four foil rule but it would be wise to have the technical committee look into that first. The four foil solution should not be applied before someone has won a big regatta with sailing on three foils. Only ban something which is both proven to be competitive and harmful for the class.