:-). Up is 50 cm, down is 2 meter draft
, a mini keel will not do the trick (especially for beaching or in shallow areas).
If you figure the time lost
to go ddw in order to take the board up and down again so you don't damage the boards swing mechanism vs just sailing a max VMG (course) downwind to follow your (not straight) course, you might end up faster one way or the other (depending on how long the leg is).
To be frank, I think there are other ways to increase speed significantly (especially for a tri) but in essence of course you are right.