The user at the top of the last couple of daily ranks isn't using a bidbot per se... so the bidbot blacklist wouldn't work in this scenario. They're using Smartsteem, which organizes random users who are selling their VP - so different names are appearing for each post with the big upvotes.
There was a solution raised in the Discord of limiting the amount of times the same user could be in the top positions, or top 10... with lower upvote percentages to share around the upvotes a little bit... obviously this would disrupt the Top 10 rankings, and maybe cause people to create numerous accounts, but I think it's an idea worth investigating since a bit bot blacklist wouldn't apply in this scenario.
We are testing @fknmayhem's theory too now. We will find out the best solution anyway cause so many great people like you guys keep suggesting great ideas :)