This discussion has had enough time to air out, to get a true sense of the situation. Imaginary Boys is deemed to pass the four little rules of validity, as it centres on a DWU element: the primary character is a Novelisor. The Novelisor(s) in this are clearly intended to be the same Novelisors from other stories which were themselves also set in the DWU.
Hearing no sustained objection, this thread is now closed for commenting, and Imaginary Boys (audio story) can now be covered on the wiki as a valid source.