Do you disagree that if authors could set (say choosing with a menu) the share of rewards that go to voters, the optimal setting to maximize the amount of net rewards going to the author would be around 50%?
I'm not even positive this is correct, but I think it may be. Remember, voters are many. If a million people vote for a post then each voter's individual contribution is worth 1/1000000 of the author's. That doesn't seem crazy to me.
I think if curation reward was a variable set by the poster it could easily turn into a game of most users not upvoting a post if it didn't fit the average poster/curator reward ratio, which I think would go below 50% and keep falling over time. It would reach some equilibrium at some point but I think the voters would have the upper hand. In the long term, creators would give up and stop contributing. Giving the power to non-creative users doesn't generally end up well for socially-driven websites.