Correct me if I'm wrong, but I thought NewDark uses DX9 to display things in modern resolutions and provide some post effects, but the engine itself wasn't re-written for DX9 (that would probably be a huge task anyway).
As for the experience, if you make models and textures mostly for Dromed, then yeah, you don't have much practice in that workflow, and that's fine. The curve is quite steep, but once you get the hang of things, its super-rewarding and a lot of fun IMO. I actually prefer making models and materials over level design.