Display related dexterity content types with eea.facetednavigation

Question

I have a site that has uses dexterity with plone.app.relationfield.behavior.IRelatedItems and eea.facetednavigation. I can't seem to query for related items. The related_to index that eea.facetednavigation uses is the Archetypes getRawRelated index, which isn't populated by dexterity. Is there an obvious way to query for related dexterity types with eea.facetednavigation that I'm missing? I checked out eea.relations, but while that allowed me to define relations, I still couldn't figure out how to query for and return the related items.