pls make DX9 possible [sharp textures, max resolution/10 bots even on single GTX970 GPU]. let players choose between DX9/DX11 as it was in rF1, thanks
That would not be possible as lots of the newer shaders depend on DX11, so the newer content would simply not run in DX9. Same with VR support and post FX libraries. In rF1 you could choose between running DX7/8/9, but DX9 today is over 10 years old, so the situation is a bit different.
Support for DX9 has ended a long time ago. During the transition phase (about a year) we still supported both but as @stonec mentions above, we are taking advantage of new features in DX11 that cannot be backported to DX9.
