GT Sport supports the Fanatec CSL Elite PS4 edition only. It only has no FFB when not using any other fanatec wheel such as the standard CSL Elite or the more expensive Clubsport V2/2.5 that I own, which makes it fucking useless.
Nobody knows if you can plug in the XB1 wheel to the CSL Elite PS4 edition and have it work for XBOX, and Fanatec hasn't directly answered that yet.
Not that it matters much, I've given up on racing games on PS4 anyways. The grass is greener on XB1 especially in 4K next month.