The Woolwax is awesome and unless Ford completely changed their frame coating since '20, it works very well and has no effect on it. They should tape off the shocks, and the skids, at a minimum. My guy taped off the body so no overspray could get on it. I am very satisfied with the Woolwax after 2 years.
I had a shop do mine. It was a 3 day job. Pressure wash everything to prep it, mask all the bodywork, wheels, etc. Spray 2nd day. Let it set up for a day before pick up. They did the full inside of my entire frame and hitch, every nook and cranny, a super thorough job. Just be careful of the shop you pick. The first 2 were repair shops doing this on the side. They do their work outside! The first guy told me my truck was too new to have it done, bring it back when it's older, because the whole truck would be completely covered in the product when he was done! Second guy was just as goofy. The third guy, the guy that I had do it, was a body/resto shop who were very an al. My kind of guy!