I usually release the downhaul and rotate the mast 90 and hoist the spi, but once in higher winds I tried to sail with the downhaul tight to get the top of the sail to twist a bit and it felt fine until I saw a picture of the mast bend!!!
I had the traveller in center and rather tight mainsheet but the mast was bending a lot to lee anyway!! Thank's to the "bendiness" of the carbon mast nothing happened, but it looked scary.
Nowadays I always release the downhaul in all winds before hoisting the spi.
On the A-class the main should be in center and rather tight mainsheet to keep the telltales happy, only when the wind is honking and the speedo is close to 20 knots does it pay off to let the traveller down a bit to get the telltales happy again. Note that I'm using trapeze from 8 knots of wind and up so I can keep the speed up, if you sit on the hull instead I guess you need to let the main traveller out earlier since the apparent wind is further aft.
You gain 30% in total righting torque on the A-class by using the tapeze compared to the "hull sitting" and you can get your weight 1-2 feet further back. This is based on 80 kg weight of the boat and a skipper weight of 75 kg.
/hakan
