Could the plasti dip be just the thing for protecting frames from cable rub etc, as they do a clear version?
Perhaps on a carbon frame instead of helitape?
Nope. Easy route is just use a decent PU coating. This is what I am doing on my carbon frame when I refinish it again. I have formulated myself a nice coating that you can abuse with wire wool and can just about make out a mark. Have helitaped up my carbon frame in all the key areas but all the other areas that get branches etc have all got a few scratches. But they are battle scars and a reminder of all the fun I have had.
But I would say helitape is still a much easier solution as you can easily remove it if it does get damaged and it is thicker so protects better against knocks and the adhesive layer means it shears across the paint instead of taking the paint with it.
So in short – some frame makers really need to use better lacquers. But helitape is still a very good solution and one I would use anyway in key areas for both extreme rub and impact protection.