Wouter and Gary,

Thanks for the additional comments.

Wouter - great story!

Gary - I hadn't been thinking about trimming the main to stall it but maybe in high winds with spi that's what you're after. Originally the comments on trimming the main were made in the context of no spi. But maybe in overpowered conditions, a partially stalled sail with low drag is faster than an overpowered sail which keeps trying to bury the bows.

Wouter - it's stil amazing to me that you get good drive with a sail as flat as you described since on my monohull dinghy, when I flatten the sail (DH, OH, and vang) in higher winds the boat is SLOW (I assume since the sail is generating no lift). However, when I add some draft down low via OH but keep the sail flat on top using the vang and DH, I find the boat drive and speed really improves.
When you flattend your sail at DCC, with mainsheet and DH really tight, how flat was the mainsail down low (ie, how far off the boom was the foot of the sail)?

Jerry