>Derek's books are quite well-known. Anyone with a reasonable amount
>of education - like, say, Azalynn - will know what they are,
>especially Parallel Dimension; it's one of the most famous titles
>in the series, along with So You've Become Unstuck in Time.

In Secrets, Gryph mentions how dimensional travel isn't unknown. In fact, there's a few examples of it throughout UF. It's likely that people know about it, it's just that they always think its something you hear of but never experience.

Matrix Dragon