Plugin / Present Callback

I don't believe it is possible currently, but is there any way to run code after the all of the shaders have been run? Even something as simple as using boost interprocess to signal my dll.

One way to send information from a ReShade shader to additional software hooked into the game would be to draw a one pixel line on one of the screen borders and encode data as colors there for the other software to extract from the frame. Other than that it's not possible currently (and would be hard in general, because the shader ultimately run on the GPU and transfering data from GPU back to CPU is an unfavorable process).