Brainstorming: I wonder what would happen if you just discard the highest value vote and lowest value vote and calculate the post's payout based on the remaining N-2 votes (but still give curation rewards to all voters). This is how they scored kata in my son's karate tournaments.
- A post would need 3 votes to get a reward.
- Self-votes would only pay off if they were "ratified" by a higher value voter and a lower value voter.
- It's still vulnerable to "gaming" by multiple accounts, but - unless ratified by others - at the cost of the sacrificed steem power in the highest value account doing the gaming.
- Not sure how this would incentivize/disincentivize whale voting.