I did soak the door in Evaporust overnight when I de-rusted all the internal doors and clips. It didn't seem to help much. I have also tried to squirt in some PTFE dry lube to see if that helps (still working on that). When I repaired the corner, I cut a piece of steel to fit into the broken out corner and bonded it into the corner with JB Weld on the inside and used the JB to reform the outer corner. That should be fully cured later today. My plan was to do similar to your fix when I reattach the door.