Helix Mod for Quantum Break stripped down to disable motion blur only. Mirrored from here.
Extract the files to <path-to-game>/dx11.
Support the autor of the fix by donating. See blog post for more information.
VectorBlur.obj file with motion blur disabled. Taken from here.
Copy "VectorBlur.obj" to <path-to-game>/shaders/build/pc.
This disables only the motion blur effect without removing other post-processing such as the "darkness effect".