I use bedliner for just about anything...
I paint all my new hardware/ shock mounts, lift kit parts, brackets... etc everything in bedliner, especially if it goes underneath the truck.
The bottom part of my truck is bedlined. Although I DID NOT stir at all, I wanted a smoother texture. The entire rear of my truck, from the bench back is lined, I used a roller for almost everything, and a brush in the corners for the bed. I used a brush for the body as well.
As we speak, I am letting the Hurculiner dry on my future roof rack pieces. I brushed it on. It goes on very easy, and self levels for the most part. The best way to get good coverage is to get the brush globbed up, and start dabbing at the surface. Takes a while, but it gets a good cover. What I do to save time is I brush it on quickly like a crappy paint job, then go back and dab quickly. I then run the brush over it quickly again to level/smoothen out the coat. the bedliner does the rest. It'll fill in small nicks and scrapes. You cant even see where we welded patches in my bedcorners. the bedliner blends everything. I was desperate/lazy one day, and used ripped up paper and Hurculiner mix, to fill in a 1.5 inch hole in my inner wheel wells that water was coming in through. Sealed it shut, and been good for 10 months.
I am a fan of this stuff lol.
Right now the can I have is super thick, almost light asphalt because I didn't stir while I did the body, I plan on using this as my third coat on my trucks door jambs and areas my boots will make contact with. Extra rubber = grip and protection.