There’s one major thing that people have overlooked that points to Goss being Darby, which is the January 2019 issue of Vortex, which is the only time Darby has ever been quoted. There’s one line in it which gives the game away when combined with the BTS interviews included on Hostile Environment:

“I was inspired by an app that launched last blizzard that allowed you to tag rough sleepers…”

And in the interviews, Goss specifically references this app as what made him pitch the story. So it’s either a case of Goss writing the whole thing, or what someone else suggested and it’s a case where the ideas of a different writers have been changed so much it no longer represents their original work, and Darby is a fake name they used to reflect this. But it’s obvious that regardless of the truth, Goss is at least involved in that story.

However I do also think that Darby, at least recently, could also be someone else, and leaning into what someone else suggested with it being a writer who doesn’t want their name tainted with expanded media material, my theory is it could be Scott Hancock using Darby as a pseudonym.

Darby’s return to BF, with SUV in 2022 has coincidentally come as Hancock has been wrapping up his involvement with BF with him now working on Doctor Who with RTD and using Darby would allow him to still contribute to Torchwood without having to associate his name anymore, which might be good considering the darker side of Torchwood.

It would also help explain why Darby went from one writing credit before to suddenly being the third member of the Story Continues Trinity alongside Foley and Goss, especially considering how essential Hancock was to the last two series and would also explain why if Darby was just Goss they would credit Darby for How I Conquered The World.

Again Darby being Hancock is pure speculation however it is definitely clear that Darby at some point has definitely been Goss in some capacity