The method used by Andy P is fairly standard, with the foam wedge being the sacrificial part, although the board usually ends up with some damage too but doesnt normally snap off and nor do you cut a slot in the bottom of the boat.
If you make the case to heavy you run the risk of snapping the board if you ground at speed so best to have a bit of give if you can.
I think I'd tend towards the Andy P method, and if you have any wear shove the board in with a bit of parcel tape (a couple of layers) around the Trailing edge and fill with Sikaflex.