Harry's system would work perfect when you are going to change settings but from what I've seen on the newer 5.8's is you don't have many alterations on these cats.
My jib setup went to a block at the top of the forestay then down to a double block that was then cleated at the base of the mast. My blocks got caught in this on a lot of tacks so I changed it to the same block at the top of the forestay then back down the luff to a double block on the foil back to the main beam to a cleat. This rotated the foil up a bit and I found it very easy to make the forestay go slack so that was obviously too much purchase. Then I saw a new 5.8 with a well regarded crew who have sailed 5.8's forever and their setup was to a small block on the foil that went to a cleat on the foil as they never changed that setting. The thing I love about the 5.8 is it's a very simple boat, they have basically one mast rake setting for all wind one jib block position and they give you time to react.