Painting over powder coat - best way?

I’ve got a Mobtown tailgate skin that was shipped powder coated and now has rusted and needs to be worked on. The skin has been installed under the factory cover. The trouble areas have all been sanded down to bare metal with some spots showing pitting. I’m not sure what would be the best way to proceed, it’s not possible to sand the entire skin down to bare metal. Would it be best to use self-etching primer followed by paint (Rustoleum) and clear coat? Or use something like this kit by POR-15 instead? TIA

$35 POR-15 Stop Rust Kit, Non-Porous Coating Seals and Protects Metal from Rust and Corrosion, Gloss Black

https://www.amazon.com/dp/B077J66P27/?coliid=I1YJNLPU4ID0Y0&colid=2YNIOYTP84AM1&ref_=lv_ov_lig_dp_it

 

I've read decent stuff about Steel-it. They say it's the closest thing to powdercoating

 

Por-15 is an awesome product has some friends use that stuff and the raved about it

 

I've always had best results with lots of prep, self etching primer and rustoleum high performance enamel. That's how I painted all my armor and it holds up great and is easy to touch up.

 

Curious to how it's even rusted with it initially powdercoated and protected by the factory cover? As for paint, I personally would repair the area and rattlecan the whole thing with bedliner.

 

Maybe I'm lazy. I'd just do what you did and hit it with some Rust Oleum.

 

Those were my thoughts too. I also have a Mobtown tailgate cap and that started to rust as well, although my KB Voodoo one only lasted one winter before the powder coat failed and rusted through.

Thinking of using self-etching primer then rattle canning with Rustoleum, after proper preparation. Basically what you guys are all saying. I appreciate the response.