pretty easy on the cat. I've raced people backwards before and it is great fun! It is difficult to maintain the backwards course if the jib is pulled out. It's much easier if you point up and let the sails flog. Stay directly into the wind while watching the water flow over the rudders. As soon as the water flow begins to reverse remember that steering is now backwards! (also useful for sailing in substantial surf). Just keep the boat headed straight downwind and it will slowly start to pick up speed and actually get to a pretty good clip this way. (also, if you have them, lift the daggerboards at least halfway).

Once you have some headway, the crew can pull the mainsail boom out gradually without upsetting the rudders...but the foils aren't meant to steer that way and they are supper sensitive!