My adult son has a Jamis bike and uses it to shop instead of owning a car. He also likes to hit up the local bottleshops and the weight is damaging the rack. He has wald folding baskets on each side of his Delta rear rack. The basket attachments and the wire grid of the baskets rubbing against the rack legs has actually worn the metal half way through! Clearly he needs a rack that is composed of some really tough metal! For point of reference, he already replaced his rear wheel with a custom wheel on a bombproof velocity rim, because the weight tacoed the original wheel.
Are there some rear racks that would be impervious to the weight and rubbing of the baskets? Particular brands or materials? The wald baskets are fine, look like new, it's just the rack that is getting destroyed.
His current rack is the Delta Super Sherpa https://www.amazon.com/Delta-Mega-Ra.../dp/B000ACAMEC

Appreciate any recommendations...