A general question of using a noun vs the gerund (
-ing) seemed inclined to think they can be used for different purposes.
In this particular case one could argue that one thing is the process and another is the result of that process, but some frameworks have a
scaffold command (Ruby On Rails, for example) making it a synonym (in the eyes of developers) to scaffolding.
There are even a few questions that refer to scaffolding as the practice of using scaffolds (as in Twitter-Bootstrap scaffolds)
Therefore I think this should follow the line of
unit-testing and be made synonyms