I don’t necessarily agree with what I am about to say because I am just thinking out loud, but …

It could be (theoretically) hard coded that there is a curation reward reduction for voting for the same account within a certain time period. The reduction could be sent to the DHF.

This would encourage people to seek new authors, follow manual curation trails, or vote for the author anyway because they provide valuable content and give up their extra curation rewards.

Alternatively, this could be implemented on a resource credit level. Voting for the same author within a certain time frame takes extra resource credits. This would encourage people to do the actions above or power up more Hive.

Making these types of changes could be framed from a chain security perspective. This change isn’t to take away rewards from good authors, but rather to ensure that underrewarded authors and found so we have greater decentralization and more users.