Something I noticed is that beneficiary rewards aren't counted towards your author rewards, so someone might "cheat" their KE ratio by setting a secondary account as beneficiary (or a service like rewards.app) and then powering up a small amount of HIVE on their main account, thus decreasing their KE while extracting rewards. It would be useful to (somehow) take this into account when calculating the KE ratio (or its more advanced versions, like the KE+). Not a big deal right now, but in the long run more people might find it out and make this value less and less useful to help evaluate someone's behavior on Hive.