I am ReShading Nascar Racing 2003 and it seems that the game uses two depth buffers.
Leaving everything unchecked in the DX9 tab, i get this buffer (cockpit of the car):
Enabling Copy depth buffer before clear operations I get this other one:
I need to merge them both in order to have some shaders using depth buffer to work correclty, basically the first one multiplied over the second.
Would it be possible in some way? Using ReShade 4.9.1.
Not 100% sure, but I think you'd have to modify the source code for reshade to expose two depth buffers to the shaders, recompile, then modify each shader that needs depth buffer access to combine the two depth pixels (one from each depth buffer) appropriately when sampled.
Not impossible, but probably harder than you hoped.