I have a question and I don't know if it was asked before. If you have a balcony as per 210.52(E)(3) and you have handrail that goes right up to the door frame, How are you suppose to mount a receptacle and still be within the perimeter of the balcony?
IMO, in building construction terms anyway, an area of that minimal size at the top of the stairs, which it sounds like your describing, would generally be considered a landing and part of the staircase, so probably not an actual balcony in the traditional sense or as mentioned in the NEC.
The NEC originally has a square footage requirement, before the balcony required a receptacle. That requirement was removed, essentially requiring all balconies to have a receptacle.
The problem is that many buildings have 'balconies' that are no wider than the patio door that faces them. While it's fine for the balcony light to be mounted above the door, or to the side of the balcony, neither location is very good for a receptacle.
Hanging it from the railing is not much of an improvement. You're still stuck with a junction box- which has to be accessible.
I don't care how 'good' floor receptacle have become, I really don't want one out in the weather in a place like a balcony deck. Plus, if you want to be out on the balcony jackhammering the deck, you're a braver soul than I!
Time for the AHJ to use his authority to waive the code requirement.
If you need to make it pretty, have the rail fabricator box in the first pair of rail balusters, up a foot or so and set an FS box in there. Then you can hide the raceway/cable where it enters the wall next to the door frame. Do it on the side opposite of the door opening (on the hinge side or pocket side) so the cords will be away from the traffic path.
Wrought Iron might be the easiest to deal with since you could just bridge the balusters with a steel enclosure and paint it to match the railing. Tougher would be some fancy power coated aluminum rail.