Have you checked Steeve out yet? It seems to offer a good front end with option to filter out bid bot posts. You have the reach to start shifting people over to front ends like that, perhaps even do a campaign for limited time where you curate only not promoted posts?

https://steemit.com/steeve/@steeveapp/steeve-now-in-public-beta-personal-recommendations-and-the-world-without-bidbots--voting-trails