I have noticed mast tang wear on my boats as well (H17 & H18) where the main shackle connects (the large shackle which secures the shrouds and forestay wires). There is wear in the hole from the shackle pin working against the mast tang. I was a bit concerned about this at first, but now I don't actually think it's that big of an issue, here's why- as manufactured, the hole in the tang is a significantly larger diameter than the shackle pin (something like a 1/2" diameter hole for a 5/16" diameter pin). When the tang is new and the hole is perfectly round, the diameter difference leads to a point load between the pin and the tang. This causes the pin to wear into the tang. As the tang continues to wear, however, the edge of the hole will begin to conform more closely to the diameter of the pin and this effectively increases surface area between the pin and the tang and the wear stops (or at least slows down significantly). After about 1/8" of wear on the tang hole, the wear seems to have stopped. Now I definitely intend to continue monitoring this, but so far, I haven't seen it get any worse. On a Getaway, changing out the mast tang may not be that difficult, but on boats where the comptip is glued into the mast and the tang rivets through the comptip, it would not be a fun project.