Same here. I always lay long materials flat. I see folks in other pickups lean the material on the tailgate. I think it's better to lay the material flat on the bed. The tailgate being down gives an extra 18" of length to support long materials. And the weight of the material is spread evenly throughout the bed floor, as opposed to the tailgate bearing the majority of the weight in a concentrated area.I leave my tailgate open when hauling wood. See to many other Frontiers with the tailgate plastic top cap missing or destroyed.
Some may point out that the material leaning on the tailgate is less likely to slide around or out of the bed. That may be true, but bundling and securing material as I mentioned earlier prevents that. The material was likely shipped to the store on a flatbed truck and secured with the same method. Having the Utili-trac with the rails in the floor helps tremendously.