I am trying to not split the cowl if it was Fibreglass no problem done a few of those. But a balsa cowl I think it would be difficult balsa does not have the strength of Fibreglass, and the crunching of the screws at the split will difficult to prevent. But if it has to be done it will be split. This is the third cowl I am making for the plane.Where the cowl is split on the full scale may help your decision.