Rails ActionCable and Ember CLI app - Resource Bottlenecks

We've successfully implemented real time updates in our app using ActionCable in Rails and implemented the consumer as a client service in Ember CLI, but am looking for a better, less-expensive approach.

app/models/myobj.rb

has_many :child_objs

def after_commit
  ActionCable.server.broadcast("obj_#{self.id}", model: "myobj", id: self.id)

  self.child_objs.update_all foo: bar
end

app/models/child_obj.rb

belongs_to :myobj

def change_job
  self.job = 'foo'
  self.save
  ActionCable.server.broadcast("obj_#{self.myobj.id}", model: "child_obj", id: self.id)
end

frontend/app/services/stream.js Here we're taking the model and id data from the broadcast and using it to reload from the server.

import Ember from 'ember';

export default Ember.Service.extend({

  store: Ember.inject.service(),

  subscribe(visitId) {
    let store = this.get("store")
    MyActionCable.cable.subscriptions.create(
      {channel: "ObjChannel", id: objId}, {
        received(data) {
          store.findRecord(data.model, data.id, {reload: true});
        }
      }
    );
  },

});

This approach "works" but feels naïve and is resource intensive, hitting our server again for each update, which requires re-authenticating the request, grabbing data from the database, re-serializing the object (which could have additional database pulls), and sending it across the wire. This does in fact cause pool and throttling issues if the number of requests are high.

I'm thinking we could potentially send the model, id, and changeset (self.changes) in the Rails broadcast, and have the Ember side handle setting the appropriate model properties. Is this the correct approach, or is there something else anyone recommends?