So, the geometry of my trailer isn't favorable to convenient aft tie downs. The trailer frame is wide, but the boat is narrow. The transom, however, is well supported by the bunks. The question is: Do tie down attach points, legally or practically, need to be to the trailer frame? I'm seeing a possible way to make a substantial attach points to the underside of the bunks that would equate to a short run for the straps which I see as a positive..less potential for slop and/or weight shift. Since I'm not a lawyer or an engineer, I thought I better ask for more experienced opinions.