Peter I like your way of thinking,some great ideas.One disagreement sometimes sailing a 16 downwind without a spi is living on the edge.I remember one particular experience,going down winnd in a line squall on Lake Superior.Breakwall about 10' to leeward.Heading up in 25-30+Knts of wind and driving rain was not an option.We ran along the break wall like this for about one mile.Luckly the squal passed as quickly as it formed.Sailing on Superior can be quite adventursome.