Experimental changes to AI perception, makes enemies significantly less perceptive at night here are the current changes:

Distance detection is reduced from 750 meters to 300 for the naked eye
Peripheral vision has been reduced from 120 to 50, the normal FOV is 90 (max for a player) so I felt it's fair to drop the peripheral vision that players don't possess. 
Humans are considerably less visible to AI while prone
Humans are noticably less visible to AI while crouched
Humans are decently less visible to AI while standing
Forget enemy time reduced to 40 seconds from 60

Cold Front PvE AI

Experimental Changes to AI perception behavior

Cold Front PvE AI

1.0.1

1.0.0