Thanks very much. I suppose I should have searched enough but I do appreciate the help.
30 years ago the AYRS (amateur yacht society) had an extended development of a boat with two centerboards (might have been dagger boards). The function was exactly the same as described here, and the boat was apparently a success - to the designers needs.
That boat was able to be steered by changing the balance of the boards, and it would follow a wind shift with no action by the sailor. Maneuvering was accomplished with the rudder. Faster sailing was proposed by raising the rudder out of the water when on a stable course.
I'll see if I can find the articles, they are typically still available to order.