ember-modal-dialog: double onClose call

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  countClose: 0,
  incCloseCount() {
    this.incrementProperty('countClose');
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.ember-modal-overlay {
  background: rgba(128, 128, 128, .2);
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
}

templates.application.hbs

<h1 {{action (mut openModal) true}}>click to open a modal</h1>

{{#if openModal}}
	{{#modal-dialog
    clickOutsideToClose=true
    onClose=(action incCloseCount)}}
  	Click anywhere to close the modal.
  {{/modal-dialog}}
{{/if}}

"onClose" has been called {{countClose}} times.

<hr>

<h3>Why?</h3>
In its default implementation, "onClickOverlay" calls "onClose". When an overlay is used in addition with "clickOutsideToClose" (which calls "onClose"), the addon does the following:
<ul>
  <li>Calling "onClickOverlay", hence calling "onClose"</li>
  <li>Calling "onClose" because of "onClickOutsideToClose"</li>
</ul>

As a consequence, "onClose" is called twice in such (common, I think) configuration.

twiddle.json

{
  "version": "0.13.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
    "ember-data": "2.16.3",
    "ember-modal-dialog": "2.4.3"
  }
}