Has anyone done this? My 2017 GLE63s came with running boards and it seems like they scratch easily. Looking to paint them with bedliner paint or have them painted. And how good are the ebay running board to replace the scratched up ones and can I just buy the aluminum piece?

I'd done that to my FJ Cruiser running boards and push-bar. Warded off scuffs and rust for almost 10 years. Even had the push-bar painted in the OEM Voodoo Blue, looks awesome

I just purchased a replacement step pad #1666900375 from my local dealer and will have it installed. The adviser on the phone recommended I either Ceramic coat them or have them coated with plasti dip for protection. Which seems like a good idea.

Forgot to mention that I used Line-X bed-liner.

Dipping them sounds interesting. Post a pic when you're done!

The dip won't last. The stuff is made to come odd relatively easily.
Get it painted with bed-liner as you initially mentioned. You can choose between textured or smooth finish. That stuff will never wear out.