A version of Paul Magrs does exist within the DWU, but, not unlike Marked for Life, there is no narrative confirmation that the books are written by the in-universe Paul Magrs.
Marked for Life • Iris Wildthyme and the Celestial Omnibus • Iris Wildthyme's Old Flames • The Fabulously Priceless Baubles of the Dalek Supreme • The Maestro of Doom • The Mauve Autodidact • The Gilded Utensils • The Extremely Lively Planet • Iris Wildthyme's Seven of Thirteen • Iris Wildthyme's Goldfinger • Iris Wildthyme's Fabric of Time Itself (MIAOW) • Iris Wildthme's Wheezing, Groaning Enigma • The Perennial Miss Wildthyme • Iris: Abroad • Wild Thymes on the 22 • Iris Wildthyme of Mars
The Confounding Case of the Planetary Prankster • The Pernicious Plots of the Big Game Hunter • The Dangerous Dilemma of the Dream Doorway • Assassin on the Railroads • The Curious Case of the Weirdling Woods
Some categorisation may be based upon conjecture. Real world information should not enter into this. Additionally, a character's role in the DWU can differ from the real world - their placement here is for categorisation.