I could be wrong, but it seems to me that the best strategy to get curation rewards is to "bet on" posts from people who already have a track record of having popular posts. If this is true then it's not clear to me that this works well as "proof of brain" so I'm not sure it makes sense to devote more rewards to it, especially at the cost of rewarding creators. Is there evidence that careful, thoughtful, content-based curation "works better" than dumb algorithms like voting for posts from accounts with good track records?
If the goal is to improve the incentive structure on the blockchain to encourage people to manually search for good posts based on their content then it isn't clear to me that this proposal does that. For one thing, since the share of curation rewards you get are still tied to impact of your vote most people won't see very big curation rewards since most users of the site don't have large amounts of SP. If the reward for identifying an awesome post is still tiny for the majority of users isn't it bad ROI for them to put in the effort? Or is the idea to try to incentivize big accounts to curate?