The primary factor with any board is the distance between the mast track and the foil mast. If this distance is too close it makes things very agile, which beginners may lack the control to handle. In my experience, some of these crossover boards tend to have the foil track very far forward, putting them into the "ultra-compact" geometry category. Ultra compact geometry makes it difficult to sail pump vigorously and it makes gybing much harder.
The other issue with crossover boards is that they often have chinned rails all the way down to the tail which seem to increase the difficulty popping up onto the foil when the wind is very light.
A crossover board is a great option if you are going to "crossover" or if you are not sure whether you want to wing or sail foil
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