OK, lets explain HOW a Schwintek system works
1. The rollers SUPPORT the room. So, if the rollers have made an indent, that usually means the bottom of the floor will be rubbing/grinding on the slide roller axle supports. NOT GOOD
2. ALL the Schwintek rack system does is move the room in and out. NOTHING ELSE. The rack system does NOT support the room at all
3. Yes, when you have the rollers indented/scraping the bottom, you can use Steel or Aluminum plates. I use Aluminum. BUT, you may have to take the Schwintek system loose to allow the rack system to lift up that 1/8 to 3/16 inch. If the room has sunk slightly, you may not have to do that. You will just be lifting the room up to its original point. Doug
PS, in extreme cases the floor has rotted and that is why the bottom filon has collapsed and causing gouges. The filon NEVER supports the rollers. The Filon is glued to the bottom plywood and that is the strength to support the rollers