There is a good bit more information on the topic, here
http://www.cruisersforum.com/forums/...ts-163122.html
Where a multiplicity of design types of fixed, retracting, folding, & removable sprits are covered. Including suppliers.
That said, yes, the
concept makes a lot of sense, & if properly engineered, makes a lot of sense. And they've been around for long enough so that the loads are known well, so that designing them properly's not too tough.
Thanks for sharing the link.