My concern would be with what it’s made off.
In my experience, one sure fire way to scratch glass is with aluminium. When I first had aluminium ladders some forty years ago, they twice came in contact with windows whilst manoeuvring in tiny gardens and both times left nasty marks that couldn’t be removed. On one it was about six inches long. A mate of mine had his ladders blown over, and they slid down a living room window causing a long arc shaped scratch on the window.
Technically the spray bar should never come in contact with the glass but accidents happen. I’ve always made sure there’s no metal on my brushes that could possibly come it touch with the glass. If I were to go this route I would want a plastic one.
Looks the biz though