backing plates

Jasper here.
OK. I'm planning to reinforce my stanchions this winter and I'm reading this in the class rules:
. Backer plates for stanchion bases may incorporate a short leg from the underside of the deck to the inside of the hull
Does anyone have experience with that particular trick? How do you attach to the inside of the hull? I'm worried about point loading.
I also notice that you can only use fiberglass or stainless backing plates. I've only really seen washers or Delrin used on boats...

backing plates