There's good news and not so good news. The spinnaclaw system works fine and would be good for a larger proa, I think at least 24'. On my little 16' Tarawa, the short spinnaker pole interferes with where I'm sitting on the hiking seat. I tried two different locations for the pivot point. First I had it higher on the mast so that it would clear my legs, but that meant that the boom had to be quite high off the deck and almost level with a high CE. I moved the pivot point down to deck level as shown in the photo but there was no way to make it work with my legs in the hull.
The good news is that it would work on a platform big enough that the crew could stay well clear on the windward platform. Certainly the balance would be better on broad reaches. So for now I'll go back to the shunting rail system I've shown in the book.