Please read Forum:Inclusion debate: Death Comes to Time for why DCTT isn't considered a valid source.
It's entirely due to the authorial intent of Dan Freedman and Nev Fountain. Arguing that it is valid despite what the production team have said about it's status as "it's own thing" seems pointless. Likewise with Shalka and COFD. I'm not sure why changing wiki policy to reflect this is going to be such a problem. There is no way for these stories to integrate themselves within the mainstream continuity.
The only way for these stories to even touch "valid" status should be through explicit referral to their events in a non-metafictional manner within other valid stories.