Shortly after I bought the boat the wingmast mysteriously broke 6' above the deck. Malcom, the builder, suggested moving the gooseneck to the main beam(like ORMA 60s) to eliminate boom induced forces on the mast. It's worked just fine, and it's easy to get across the tramp, either fore or aft, and mast rotation is induced otherwise. After the modification, the general consensus came to be that the mast was probably damaged in transit at some point. So I could move it back up to the mast, but I'm generally lazy. So sloth is the real reason the boom is rigged that way.
Dave