I will say that since lens flare is an optical phenomenon due to looking thru glass that maybe another similiar effect is better anyway. Simply put lens flare for this doesn't really make sense to me.I do think some flexibility is in order. In other words getting a certain effect may just not happen the same way in carrara, but I wouldn't throw in the towel. If you could give a specific example it helps like the one above. Understanding someones very particular effect can escape others.

No need to think outside the box....
    Just make it invisible.