Ok so what we have here is a solid piece of webbing. There's the bolt rope that goes into the slot, and then the holes burned into the webbing for the lacing. There's a 3/8" fiberglass backing rod to support it.

The theory (that has worked for me):

The reason why the old style tramps pulled out of the slot was because the groove in the hull expanded gradually over time. Then came the webbing straps - but the problem with that was that it only put pressure on the bolt rope at very specific points, like right at the daggerboard trunk, and that eventually pulled out of the slot too, or it slowly sliced itself apart over time. The solid piece of webbing with the fiberglass backing rod spreads the load out evenly before it gets to the bolt rope. Its worked for me, and worked well. Only thing to be careful about is the ends will fray.

This set I ordered have reinforced ends to account for that.