This is a pretty overblown claim that you've read. I've applied FF 3 times since I bought this truck and have had zero issues with it "taking the wax right off" like some swear it will. I'd be happy to provide more pictures. After coating the wax, it became slightly softer and seems to almost self-heal now, but still sticks to the frame just fine. The last thing you want is the factory wax to become hard. Hard wax likes to become brittle and either peel away frome the frame like we've seen in this thread, or worse, wick water and road salt between it and the steel frame, rotting the steel while looking like it's still protected by the coating.
I was just under my truck last week and found large areas under the bed that I missed while applying the FF and those areas look just like COP TZR's frame. The wax is flaking away and peeling at the edges of the cross members. So now I have to scrape all the wax off, apply rust converter, paint it, and hit it with FF. Why would I apply the same shitty wax that failed to do it's job the first time, not only on my truck but every guy that's been to this thread for help. That's just stupidity. It's not like the K2XX trucks suddenly have an issue with wax peeling off the frame that GMT900 trucks didn't have. Look under any GMT900 truck in the Midwest or Northeast and it'll be pretty obvious.