Mako - A good installer can custom cover any part of the vehicle you'd like... I've seen entire exotics wrapped (Audi R8, Ferrari, etc.) but the typical patterns are designed to protect against common driving damage caused by frontal impact of small objects.
The problem with doors is that it is the size and weight of the impact - a car door swung into you car is going to leave a crease or dent, regardless of PPF. The only salvation there might be that a good dent repair guy could get it out and the paint is not damaged.
It can be done - you'd just have to find the right installer and negotiate the price.
Actually - you should hone your skills and become a pro installer. I just want to be able to say "Uh-oh, better get Mako!"