I can be misunderstanding the problem(English isn't my native language), so correct me if I am wrong:
You want to be able to work on files to load inside arrays, but only for your convinience (so the user shall not be able to edit it).
If that is the case, I think it is possible for you to create another quick project on C2 to have an JSON array editor suitable for your needs, then, you just put the retrieved content in a .JSON file, which you include in C2 project files, and load into arrays using the Ajax object.
I am not sure on how to do it, but creating an easy-to-work-on array editor to make array editing simplier, then use them into the original project may be the solution to need
If someone has a better idea, Or if I am All wrong, correct me please.
Game design is all about decomposing the core of your game so it becomes simple instructions.