We recently shortened the Aussie forestay by 4 inches to 19 feet, but since the last Worlds in Mexico we were at 19' 4 inches. Yes the mast looked to be leaning aft, but to allow maximum mast rake we used the longer length. The rigs stayed on the beach that way for 3 weeks with no problems.

The maximum mast rake is block to block on the mainsheets using smaller diameter sheeves... and the shrouds loose to allow the mast to lean to leeward. We saw this rigging at the Neumea Worlds. Light "junior" teams were doing it so they could hold the boat down in the high winds.

For USA production we then took the 4" out. They still lean very far aft for the average guy. Well for that matter, the length we used starting after 1982 looked way aft to a lot of people. In the last few years we were even recommending a second ten hole adjuster on the forestay to get the rake people wanted. The new length just copied that.

The forestay is only a rigging helper, not a structural wire. The jib luff wire becomes the forestay once the halyard is tensioned. If you want the mast tensioned when the sailes are down, you can shackle the jib halyard to the forestay adjuster and tension the halyard. If the halyard is not long enough, add a length of line tied to the adjuster to reach up to the halyard shackle.