Huh. that's different. I'm still trying to wrap my head around the advantages of that over the traditional method of pinning the spin pole to the leading edge of the front beam and supporting it from the forestay. With the spin pole running all the way to the rear beam and through the dolphin striker rod would also be pretty tough to disassemble for trailering but it doesn't sound like that's on your list of needs.

Any side to side or fore/aft moments induced by the mast are usually carried by the front beam and how it's keyed into the hulls so the need for a pole there were eliminated in the 80s. The early versions of the Nacra 5.2 (I had one) had a bar that connected between the front and rear beams to prevent the beams from rotating. It sat in the middle of the trampoline and was commonly referred to as the "knee knocker". It was pretty obstructive. Later versions had the front beam pinned to the hull straps (literally a rivet that was drilled through the straps and into the beam) in order to carry the moment arms induced by the mast loads and prevent rotation.

One concern I would have with that pole, and this is from some direct experience...is that in a capsize, it looks like it's possible to slide your leg(s) between the trampoline and that pole and get trapped (and/or injured) there. That would be my biggest concern.