I wouldn't really call that an echo chamber, then. An echo-chamber is where you are only exposed to one side of viewpoints, that's largely impossible for Hexbear users but is entirely possible for, say, Lemmy.world users. The alternative is to let liberals, fascists, etc roam freely, harassing users and creating an unsafe space for marginalized comrades that use Hexbear precisely to avoid such situations for a tiny portion of their lives.