The sliding pin alteration will be interesting. Would it be worth only do one thing at a time so that you can be 100% sure what fixes it?I watched some videos and I am convinced the rust on hub surface could cause this. Even though I spent 1hr cleaning hub surface with wire brush on a drill, I did start to chip the dirt off by a screw driver following a video on utube. They do come off even do wire brush couldn’t. I ordered hub surface cleaner that sits around studs that should arrive tomorrow morning. I feel I can save the hubs. Also, I am going to drill the sliding pin rubbers with a 13mm drill bit to make it bigger. I am not sure if it works. The idea is to have pins free when calliper gets hot.
As a side note, the more I read this thread the more insane all this time and effort seems.