New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

{{#with (component 'my-component' a='base a' b='base b' c='base c') as |myComponent|}}
	<input type="checkbox" onchange={{action (mut shouldOverride) value='target.checked'}}>
  <br>
  {{#if shouldOverride}}
  	{{component myComponent a='overridden a'}}
  {{else}}
    {{component myComponent}}
  {{/if}}
{{/with}}

templates.components.my-component.hbs

<ul>
	<li>A: {{a}}</li>
  <li>B: {{b}}</li>
  <li>C: {{c}}</li>
</ul>

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-data": "3.2.0"
  }
}