I tried making this work with DX12 but with no luck.
The profile for RDR2 installs the hook and works with Shadow of the Tomb Raider on DX12 but of course isn’t SBS. Even if the dxgi hook is installed switching back to the SOTR SBS profile won’t hook into DX12.
I don’t think there is any DX12 game with a SBS profile in the official list and it’s probably not possible to create a custom one. It would be nice to have one so it can be used as base for other games (even if native SBS support in games is scarce).
SOTR is probably intentionally nuking DX11 performance for marketing. There should be no reason to get 1.5-2.5x more FPS by switching to DX12, but that’s how this game behaves.
(I’m aware this is an old thread :)