I rewrote how I was intending to do my opening several times over the course of development and still have not actually put it together. This is because as I worked on developing the core mechanics, I found that things deviated from my original design decisions whether due to my programming limitations or as a result of organic shifts in the core engagement.
I just feel that both from my experience and all I have read & watched regarding game development that you shouldn’t focus more than a bare skeleton on such early things which substantially are minor portions in the overall development cycle that are dependent upon other systems.