Fixed low aspect ratio (LAR) keels, is the 'high tech' name for these I believe.

They do not create the same amount of lift as boards do, for the same drag ratio, so racers dont use them. Going to windward in waves, they are inferior to boards.

On cruising boats they sound like a good idea, as they are useful when beaching/dry out, protect rudders and propellers in the hull, are more substantial than boards, dont snap off if you hit something, or slice the daggerboard wells.