According to the volumetric fog thread:
The volume textures used by Volumetric
Fog are relatively low resolution and
aligned to the camera frustum.
Volumetric Fog uses a heavy temporal
reprojection filter with a different
sub-voxel jitter each frame to smooth
out the aliasing. As a side effect,
fast changing lights like flashlights
and muzzle flashes leave lighting
trails. Disable volumetric fog
contribution on these lights with
‘Volumetric Scattering Intensity’ set
Besides setting it to 0 is there any other way (even if it means changing some values on the engine’s source code) to increase the update frequency to minimize the trails?