While I am nearly always complimentary of the PDQ and the attention to detail of the designers, everyone makes mistakes. But in this case I can't imagine what they were thinking. It is not just a yard fitting error, since the starboard bow is identical. It's a design error.
For the record, it never did damage either the webbing chafe guard or the line,since the webbing stay stationary relative to the edge, and the rope glides inside. But I still did not like the look of it. A really strong wind could change things. But it does make a strong statement about the benefits of free-floating chafe gear.
With heavy docklines and my normal heavier bridle this little slot between the rub rail and the deck is too small to be accessible and in 6 years has never cause a problem. However, as I started experimenting with lighter bridles for a Practical Sailor article on mooring loads, I found the thinner 8 mm line could slide right into the slot and that the slot is quite sharp, able to slice a line in minutes to hours, depending on the load.
The chafe gear does a fair job of keeping it out of the slot, but I would rather eliminate the slot. My first thought is to fit a block of something into the space, matching the rubber and secured with a screw and 3M 5200. I'd rather not obscure the forward beam bolts.
While not the prettiest fix--I may trim this to make it purty--this does solve the problem. I cut a rectangle of 3/8" thick mud flap, laminated it to 3/4" thick, and trimmed it to fit the space. I then glued it in with Loctite PL S30. This sealant has virtually the same properties as 3M 5200, with slightly better elasticity. It is also available in white as Loctite PL S40, the only difference being color.