I suspect that the reason behind BIMARE's decision is the low interest towards F16 cats in at least three of its main markets: Italy, France and Switzerland.
However I am sure that if, for istance, the UK importer (JJcats)placed an order for a few - fully F16HP complaint - X16s, BIMARE would be pleased to build heavier hulls and fit a shorter mast on its 16 footer.
As Wouter wrote in a recent posting some kgs of resin do not cost much and BIMARE has already built a couple of its autoclaved masts for a F16 owner.
In the next season many of you will have the opportunity to find out who is this guy.
It goes without saying that these masts are both fully optimized to the needs of a F16HP, but with different bending characteristics.