Steve-
Thanks for the reply- The diagram would be interesting to see. These "automatic" devices are interesting but take a lot of initial adjusting I think to work just right. Like the "A" cat system whereby the mainsheet tension also influences the diamond tension- so as one sheets harder one gets more diamond tension which induces more "prebend" automatically- But getting the "right" amount of prebend at a particular sheet tension (for a particular sail and mast!) is the hard part. Perhaps some combinations of these "automatic" features would work better together than alone?

Kirt