For D3D12 compatibility the 64-bit .dll from this topic or newer would be good.
This file and then renamed as DXGI.dll in the game folder would be my method as a local DirectX injected .dll for the game.
https://discourse.differentk.fyi/uploads/short-url/ukf24kedNqLriRnzcWrO4najqv4.7z
Due to the bug fixes and improvements I believe the main advantage remaining is the SpecialK framerate limiter much of the other initial issues have since been resolved. 
EDIT:
https://cdn.discordapp.com/attachments/792979353117524009/794054615447896064/SpecialK.7z
December 30th .dll files from the Discord channel.
There’s a January 1st compile somewhere I think that’s the most latest compiled version but I don’t think there’s too much of a difference over what this has.
EDIT:
There.
https://discourse.differentk.fyi/uploads/short-url/gKB7HDE4T8SU7IPBZIRk0q4ctHw.7z
These contain various DirectX 12 / D3D12 improvements and changes.
Discord one should be good overall can also use the Discord channel from the above links with the wiki, download and such for additional info or help if required I haven’t seen Kaldaien active on these forums in a few days but he might be online on the Discord server for example.