For rendering linear media Unreal Engine will take into account shutter angle. I haven’t tried to see if it also takes into account the shutter speed that the Post Process Volume uses for exposure. I’m guessing it does not.
You might need to set up your own sliding scale for motion blur amounts desired for fast shutter speeds and slow shutter speeds and just fake it. As far as I know, the real-time post process motion blur is not tied to physically accurate numbers like this.