Thanks for joining in the discussion. When did you make the tests if I may ask? Because allow_curation_rewards = false definitely does something - the post then has total_vote_weight of 0 even with positive votes on.
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Some months ago now; long enough that I don't even remember who it was that started the discussion, except that they thought the same thing as you do - that authors could turn off curation rewards by setting that flag. That's obviously a pretty big deal if true, but it turned out not to be.
However you should definitely do your own testing.