The narrative device of the daydream or the classic dream-that-feels-real can be used to give a "candy" to the reader while things are (slowly) building up. It has to be used wisely because it risks to spoil the rest of the story (IMO).
For example here in AWAM it made sense for Larry, when she started visualising the dirty fantasy he was telling her, or for Sam's dream, to give a visual of his account. They were part of the build up and they fit well in the narration. There are other circumstances, e.g. at the mall when Dylan told her about the meaning of MILF and what the other students say about her which got Sophia having "lewd thoughts" that didn't require visuals, the text (again, IMO) was enough to convey the idea and tease the reader.
Provided that we don't know exactly what is going to happen in the bonus scene (although the premise that you describe it's the hypothesis with the most consensus), I don't think that having an explicit sex scene directly involving Sophia as a daydream (with animations!) will be a good idea for the story at this stage. This is just my feeling, of course, and also it depends on how it would be made and told, there is always a way. But, idk, I think it will spoil too much the story.
My 2 cents