Acceptance testing async models in ember.js

I have many async relationships in my ember-data driven application. I use a 'create default record' pattern in the router which I am having trouble getting to run properly in the application's test mode.

A report has a seriesSet. If the seriesSet is not already created I have to get some dynamic values from an endpoint, use the value returned, and fill in properties on the seriesSet.

The relevant parts of the model:

export default DS.Model.extend({
  // snip
  seriesSet: DS.belongsTo('series-set', { async: true }),
  // snip
});

And the relevant parts of the router in question:

  model: function(){
    var self = this;
    var report = this.modelFor('report');

    return report.get('seriesSet').then(function(seriesSet){
      if(seriesSet === null){
        seriesSet = self.defaultSeriesSet();
      }
      return seriesSet;
    });
  },
  defaultSeriesSet: function(){
    var self = this,
        backendService = this.get('computationBackendService');

    return backendService.series().then(function(backendSeriess){
      backendSeriess.setEach('selected', true);

      var seriesSet = self.store.createRecord('seriesSet', {
        seriess: backendSeriess
      });

      return seriesSet;
    });
  },

I'm not sure where to set the Ember.run statement. Shouldn't the promise resolver from model -> setupController take care of everything? And if not, how can Ember.run be used when I chain return statements (and not set a property from the backburner).