Inside Tire Wear?

Had new dexter axles installed a couple of years ago while on a extended trip to Alberta, Canada. Long story about that but jumping ahead, when we got home my son noticed wear on the inside of the XPS Ribs I had on the axles. Had the wheels aligned at a shop here where we live. It's a process I watched and when the guy used a sledge hammer to more or less bend the axles while watching the electronic setup he had, I was kind of taken aback but apparently that's how it's done. New tires(XPS Ribs) have been installed this year in May because the old tires aged out but didn't wear out. Have done 3 trips this summer and no sign of wear. Next summer we will be heading out west again.