Fyi, undying rage does not provide immunity. It provides 99% damage reduction, if you are doomed, 1% of dooms damage will still kill you. As for camaflogue, as far as I know it cuts all incoming damage by 50% for the entire duration. I am not sure why it would not cut lightning damage by 50%. Are you sure that it doesn't?
In my experience force camo does make a huge difference.