You really don't want to use a Dyneema based product for rigging because of the creep, unless you go with the Dyneema DUX - very expensive. It's preferable to use a Vectran based substitute. However Vectran products are not as resistant to chafe and UV exposure, which requires some sort of protective coating (usually shrinkwrap, which increases the weight and windage. The amount of weight savings for synthetic rigging on a beachcat is minimal. The a-cat guys are fanatics about weight, and you rarely see it on their platforms.

Just my humble opinion.