Can't help with your questions, but for chainplate location, what have you referenced this against? If taken from the Taipan, then this can be moved further aft. Taipan location was to allow the main to get out as far as possible, as people were sailing straight downwind at the time of design. We no longer do that, so can move chainplate aft and this takes some of the load off the chainplate due to the triangle to hold the mast has a large base. Boyer tried to get the Taipan class rules amended to allow this about 7 or 8 years ago.
