I laminated 6mm okoume to either side of my leeboard where it mounts to the bracket - specificaly the upper third.  Ive not had issues in the past with a broken leeboard but toothpick had its sheered off from open sea and another sailrig [not CLC] had its leeboard cracked in half.  I dont ever wan t to be offshore without a working leeboard.  I added a little length to CLC's leeboard  so the thickening of the board where it mounts was prudent.

Jus sayin.

Pete