Or designing a mechanism or environment that makes it easier for existent LW contrarians to express their ideas.

(My personal experience is that trying to defend a contrarian position on LW results in a lot of personal cheap shots, unnecessarily-aggressively-phrased counter-affirmations, or needless re-affirmations of the LW consensus. (E.g., I remember one LWer said he was trying to "tar and feather [me] with low-status associations". He was probably exaggerating, but still.) This stresses me out a lot and causes me to make errors in presentation and communication, and needlessly causes me to become adversarial. Now when discussing contrarian topics I start out adversarial in anticipation of personal cheap shots et cetera. Most of the onus is on me, but still, I think higher general standards or some sideways change in the epistemic environment could make constructive contrarianism a less stressful role for LWers to take up.)