Hey rguild. I have a solution for you, although if you're a stickler for getting to the bottom of the problem, you're probably not going to like it.
We have a '10 Southwind. Bought it in '19 and had the carpet on the main floor replaced with LVT flooring. Within a year or so we noticed scratches in the new floor being caused by the full-wall slideout, right in the center where I believe the 10-year-old slideout has a bit of a sag. Previous owners wouldn't have been aware of any problem because it was dragging on carpet back then.
Our solution was to place 2 plastic "skids" down on the floor where the scratching was happening. "Lippert RV Carpet Protectors" on Amazon. We now put those in place each time we retract the slide, and it has prevented the problem from getting any worse. (It beat trying to pry up the slide floor and replace rollers.)
To conceal the scratches already in place, we applied a liquid product to the scratches. "Wear Max Scratch Concealer", also from Amazon. This worked wonders on the LVT floor. Not sure what kind of flooring you have.