Unfortunately, you come across as highly antagonistic to a screenwriter (a) whose script was almost immediately made into a brilliant, popular film  and (b) whose story was foundationally about the way language affects our thinking.
Your main argument is that people's scripts will get rejected if they don't chain them into a box and use peculiar little brass fasteners to hold them together. This inclines me to believe that you've not yet actually seen "Arrival."
Sometimes I think a little change in the film industry would be productive, if it meant we'd get more movies like "Arrival," even if it means breaking rules, and fewer movies like "Captain America: Civil War," who follow the rules but composite dozens of mismatched absurdities and are basically mass-market children's cartoons.
 Common knowledge. By the way, championing your knowledge of "how HN works" WRT references just sounds self-congratulatory.
The bit about the footnote styles was more to help HN readers who are not screenplay experts validate an example from their world where formatting styles communicate in-group vs out-group status, because as you point out "everyone" knows footnote counters start at 0 on HN.