Replace C:\Program Files (x86)\Steam\steamapps\common\ARK\Engine\Config\ConsoleVariables.ini
with this file.
If you want just lighting disabled use this:
BaseDeviceProfiles.ini
; frame rate
+CVars=r.oneframethreadlag=1
+CVars=FrameRateCap=60
+CVars=FrameRateMinimum=60
+CVars=MaxSmoothedFrameRate=60
+CVars=MinDesiredFrameRate=30
+CVars=MinSmoothedFrameRate=5
+CVars=t.maxfps=60
; disable general lighting
+CVars=ShowFlag.Lighting=0
+CVars=ShowFlag.DynamicShadows=0
; disable fog and darkness, eg in rag castle cave
+CVars=ShowFlag.LightComplexity=0
+CVars=ShowFlag.DynamicShadows=1
el original es el que viene por defecto
?