AMD's Robert Hallock, frequenter of the PC Perspective live streams and a favorite of the team here, is doing an AMAA on reddit today. While you can find some excellent information and views from Robert in that Q&A session, two particular answers stood out to me.
Asked by user CataclysmZA: Can you comment on the recent developments regarding Ashes of the Singularity and DirectX 12 in PC Perspective and Extremetech's tests? Will changes in AMD's driver to include FlipEx support fix the framerate issues and allow high-refresh monitor owners to enjoy their hardware fully? http://www.pcper.com/reviews/General-Tech/PC-Gaming-Shakeup-Ashes-Singularity-DX12-and-Microsoft-Store
Answer from Robert: We will add DirectFlip support shortly.
Well, there you have it. This is the first official notice I have from AMD that it is in fact its driver that was causing the differences in behavior between Radeon and GeForce cards in Ashes of the Singularity last week. It appears that a new driver will be incoming (sometime) that will enable DirectFlip / FlipEx, allowing exclusive full screen modes in DX12 titles. Some of our fear of the unknown can likely be resolved – huzzah!
Ashes of the Singularity wouldn't enter exclusive full screen mode on AMD Radeon hardware.
Another quesiton also piqued my interest:
Asked by user CataclysmZA: Can you comment on how FreeSync is affected by the way games sold through the Windows Store run in borderless windowed mode?
Answer from Robert: This article discusses the issue thoroughly. Quote: "games sold through Steam, Origin [and] anywhere else will have the ability to behave with DX12 as they do today with DX11."
While not exactly spelling it out, this answer seems to indicate that for the time being, AMD doesn't think FreeSync will work with Microsoft Store sold games in the forced borderless windowed mode. NVIDIA has stated that G-Sync works in some scenarios with the new Gears of War (a Universal Windows Platform app), but it seems they too have issues.
As more informaiton continues to come in, from whatever sources we can validate, I'll keep you updated!