If there is a decision on WHO is going to be the student and what is going to be taught, academic standards can be found. US federal ones are public. State ones are harder to get but also public and most align with federal ones.
Content development would not necessarily have to limited to these standards obviously there are a whole new and more relevant set now that are not being addressed. However, the old ones are still important and unless anyone is apt to come up with all new ones, the old ones are a good place to start when constructing lessons. There is no law prohibiting the addition of standards unless those standards prohibit a student a student from participation due to disability. And even then it is only if said student does not make progress.
Just had to add that because content creation is facilitated when desired outcomes are evident. Standards do that.
That being said, the only limitation to content is creativity(and some laws).
Forgive me now. You have no idea how much time it will save.