Since it seems that a lot of people still want this and no one bothers to make it, here is a simple mod which removes the hitmarker when shooting. Drag the file into your game folder and enjoy. Please note that you need to have an ASI loader for this mod to work.
I have not tested this mod much (< 5 minutes), so if something else breaks, please let me know.
Disable any reticle color change
In the .ini you can set “DisableReticleChanges” to true to disable any reticle color changes.
Credits:
LMS