[SOLVED] How to automatically select proper DX11 depthbuffer?

Simply uncheck "Use aspect ratio heuristic". Your buffer is 2048x2048, which is a 1:1 aspect ratio and clearly different than your screen aspect ratio, which is why ReShade won't pick it if that option is active. But if the option is not active, ReShade is allowed to pick it and will do so, since it is the one with the most draw calls.