Hi Jerry,
1)Cat sailors don't complain about lee helm with spinnakers up for two reasons. One is that there is nothing they can do about it; they have already bought their boat. Two is the other boats have the same problem so live with it.
Other examples of this attitude: H16s tack so poorly that the time and distance lost due to tacking usually outweighs the advantage of a new tack, so why tack? Who complains? It is the same for everybody in a H16 race, so what the heck.
H16s pitchpole easily on a reach so you can't be too aggressive and drive the boat hard in a breeze or you will pitchpole. Who complains? It is the same for everybody in a H16 race, so what the heck.
I see nothing but praise for the H16 on this forum. In West Palm Beach, Florida two sailors have lost their lives because of the unsafe characteristics, easy pitchpole tendency, of the H16 design. It is the same for everyone sailing a H16 so, what the heck.
2) With spinnaker up and sailing downwind, a given boat design sails to a constant relative wind angle depending on the wind strength. The direction of the boat may change in the puffs but the sailor tries to hold relative wind angle constant at max VMG downwind. If relative wind angle is held constant, then sail trim is held constant and CE does not move around once the sails are set and the boat is up to speed. When the CE goes in front of the daggerboard, you've got lee helm. So what, it is the same for everybody, what the heck.
Bill