Ultimate Bunk Boards

I don't worry about wear because my boat is aluminum, but I'm just curious... Are any of you guys seeing gelcoat wear on fiberglass hulls from the synthetic bunk boards.

i've been using uncovered wood boards for years now with no visible effects. i don't trailer my boat a lot, it's in slings in my boathouse, so this might not be for everyone. i looked at using trex, but was too expensive.