Have you ever read a book with a story within it? I have.
A notable example includes “The Tale of Three Brothers” in “Harry Potter.” In cartoons, there is “The Crimson Chin” in “The Fairly OddParents,” and “The Justice Friends” in “Dexter’s Laboratory.”
In a book I read, it started out with a background description as well as a bunch of characters. One was an old lady reading to a group of children. I would have continued that story, but it bored me since after several pages, I couldn’t get to the action. The woman just kept reading.
I agree with many experts that stories should start as close to the inciting incidents as possible. Prologues are also not recommended these days unless done exceptionally well.
Anyway, back to the topic. I don’t think the story in a story idea should be reserved for top authors. However, it should be relevant to the main plot, engaging, and not too long. Otherwise, the reader might give up.
You could do a spinoff as long as it will work and keeps your audience engaged. I have a spinoff of my current book series in mind. I won’t spoil anything, but I will say that it’s not a story within my books. It might be years until I write it, though.
Do you like stories in stories?