This is great! As someone who has used bounties since pretty much the start of the program I've voiced this concern a few times over. Never wanting to be a nag about it I've tried to deal with the nonsense directly.
Really don't like idiots showing up just in an attempt to get part of the bounty, posting a completely worthless comment, and then adding multiple upvotes from their multiple accounts. Worse they love to drop in right before payout.
At 5% it's hopefully not enough to be worth the effort to spam bounty posts. But at the same time will allow those who get multiple votes from the community to earn a little more.
Great move IMO. Thank you for your continued efforts to improve this program.