Hi Simon,
at least the 5.9 setup removes the requirement to uncleat (often forgotten) and can easily be trimmed from either side. I also suspect barber hauling both sides at once may slow the sheet running through the blocks during gybing. Do you have a copy of the 5.9 manual showing the barber hauler arrangement to post here for ButchG as the diagram no longer appears on the website?

Cheshirecatman