ember-changeset and moment objects if not using template helper

controllers.application.js

import Ember from 'ember';
import { computed } from '@ember/object';
import Changeset from 'ember-changeset';
import moment from 'moment';

export default Ember.Controller.extend({
  changeset: computed(() => {
    let c = new Changeset({});
    c.set('date', moment());
    return c;
  })
});

templates.application.hbs

<h1>ember-changeset and moment objects</h1>
<p>Open console to see that it's working if changeset is constructed in code. This is not working if changeset is constructed by template helper as shown <a href="https://ember-twiddle.com/f38bf913c6c44079ba0c84c148cc9f05?openFiles=templates.application.hbs%2C">in this twiddle</a>.<br/> <a href="https://github.com/poteto/ember-changeset/issues/229">Related issue</a></p>

{{!-- It's a proxy --}}
{{log changeset.date}}
{{!-- moment operation throw an assertion that .get() must be used on proxy --}}
{{moment-format changeset.date}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-changeset": "1.5.0-beta.0",
    "ember-cli-moment-shim": "3.7.1",
    "ember-moment": "7.6.0"
  }
}