I'm not sure about the bedliner, or undercoating products, but plasti dip is 100% oil soluble. If it gets diesel, or any other solvent on it, then it breaksdown. Once that's the case, trying to match it, without it looking 'patched' is difficult. Also, if in a hot climate, short of any solvent, it's a pita to get off.
Not knocking it, I did the black highlights on my truck with it first, as I wanted to be able to remove it should what was in my mind's eye not be the greatest thing once on the truck..... Worked great for that. I've left it on, it still looks okay, but I've been really careful with any lubes, such as wd-40 since then(actually was spraying wd-40 on a project close to the truck, and the overspray droplets ate holes in the plastidip).
On larger surfaces though, which I've tried, at least in my case I couldn't get it to blend very well, and you could see the different coats; I think paint is a lot easier to feather in.