Is code-folding necessary? Instead you could put the demonstration in an appendix, and the authors would be free to decide what goes in the core of the article

Is code-folding necessary? Instead you could put the demonstration in an appendix, and the authors would be free to decide what goes in the core of the article and what goes into the appendix. This could be made automatically where trunks of article would move back and forth from the core to the article and vice-versa, depending of what the reader chose to, and in each case a corresponding pdf could be generated.