I have a 13' RIB with a glass bottom. In total it weighs about 110kg. The bunk system was worn out and had worn some gel coat prior to me buying it. So now its got rollers. Is it a problem all the weight of the boat on the keel just sits on the middle rollers, or should the wobblie rollers also be supporting the hull? Just a bit worried the wobblie pattern will leave a print in the glass.