at the crux of this issue are two facts:
1. my oldest brother is an alcoholic and seems sure that he will never be able to quit or stop being an alcoholic.
2. my neighbor and good friend is a recovering alcoholic also and I've visited AA meeting as a friend / family / ally in support of him. He says "idle hands do the devil's work" and that he does not believe that many addicts will stop themselves from engaging in their behavior if they're bored or idle.
So we know that morality is never absolute.
We also know that NOT everyone has the same moral stamina.
This means that different moral concepts must work for different people. In fact some sources say that philosophy and morality are built for the PROTECTION of sages, because they do not really need to restrain their nature like people of lesser stamina do.
So, the question is: is it wise to conclude that false beliefs are "ok" in some way for OTHER people who may be dealing with addiction or other issues, even if they're false. Clearly, not everyone is meant to be an Epicurean. And it's also clear to me that people with addiction or other character problems need a different approach to applied philosophy than the rest of the population.
I don't have all the answer, but if moral absolutism can help my brother overcome or manage his addiction to alcohol WITHOUT too many bad side effects, his false beliefs may be of utility.