Excellent post and important topic!
I never look at the trending posts exactly for this reason. Any upvote on them just favors the already well rewarded posts. If @peakd could create the opposite, e.g. posts with hardly any rewards but of a certain length or level of interaction, that would be great.
And yes, I check in the meantime regularly the KE-ratio (with this tool) of users I don´t know before I give any bigger upvote.
An additional but somewhat provocative idea could be a regular (e.g. daily) automatically generated (according to some rules) list of potentially over-rewarded posts and users with some free downvoting mana could scroll and pick some for downvoting - I know that many are afraid of retaliation downvotes but maybe some whales/orcas could interact or be ready to act against retaliation downvotes by upvotes to those brave quality curators. Just brainstorming.
The rules of what is considered as over-rewarded are of course tricky, but the level of repetitiveness vs. original content and a lack of comments in comparison to the rewards could be a first indication.