FYI- I agree bed liner does look nice for rock sliders, but the problem we have run into our here in Arizona, is that when you actually slide on the rock sliders, which happens a lot on our trails, the bed liner actually tears off in chunks.
I have tired powder coat and same issue, once scratched you can not repair. Our infamous 1990 Red Truck had beautiful Ancient Black Hammered rock sliders, but once scratched, they are always scratched and still are.
My suggestions for my rock slider customers is Rustolium Hammered as when you scratch them, you simply re-spray them.
The tearing off in large chunks is the issue with the bed liner. If you want to test it, get a piece of plumbing pipe and have them do a test coating, then drag that test pipe over a rock, but push hard a 3rd Gen is tipping the scale at 5,000 pounds.