Though uncommon, this created an opening for malicious users to wait until the lockout period to issue punitive downvotes so that they couldn’t be countered with upvotes.
Velocity will address this potential scenario by modifying the lock-out to a cool-down. After Velocity, upvotes and downvotes will both be allowed during the last 12 hours of the payout period, but their strength (for the same amount of voting power) will decrease linearly from 100% to 0% over that 12-hour period. In other words, it will take twice as much voting power to have the same impact on a post’s payout if the vote is done with only six hours left on the payout window instead of twelve. An upvote or downvote cast during the last minute would have virtually no impact on a post’s rewards.
This change will help ensure that no matter when a post receives an upvote or downvote, users will be able to counter-vote. This will also help to stabilize the potential payout of posts during the last 12 hours by decreasing the strength of votes as it gets closer to the payout time
RE: Proposal to return the 12 hour voting window gate