Jules,
you may use a different self cleating clam for the halyard which is commonly used in the European boats.
www.sport-mohr@t-online.de sells them.
It is a lot easier than with the American ones to adjust the rig tension. In a race if we are not satisfied with the tension upwind, we adjust it on every downwind leg.
One should train that, once familiar, it is a huge gain.
Fritz