New Twiddle

components.my-component\.hbs

<button local-class="run" type="button" {{on "click" (perform this.countToTenTask)}}>Run the global countToTenTask via a local task</button>

components.my-component\.js

import Component from '@glimmer/component';
import { dropTask, timeout } from 'ember-concurrency';
import { tracked } from '@glimmer/tracking';

export default class extends Component {
  @dropTask *countToTenTask() {
    yield this.args.count.perform();
  }
}

controllers.application\.js

import Controller from '@ember/controller';
import { action } from '@ember/object';
import { tracked } from '@glimmer/tracking';
import { dropTask, timeout } from 'ember-concurrency';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
	@tracked showComponent = true;
	@action toggleButtons() {
    this.showComponent = !this.showComponent;
  }

	@tracked counter = 0;

  @dropTask *countToTenTask() {
    for (let i of new Array(10)) {
      yield timeout(1000);
      console.log(this.counter);
      this.counter = this.counter + 1;
    }
  }
}

templates.application\.hbs

<div>{{this.counter}}</div>
{{#if this.showComponent}}
<div>
  <MyComponent @count={{this.countToTenTask}} />
</div>
{{/if}}
<button {{on "click" this.toggleButtons}}>I don't need this component anymore</button>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0",
    "ember-concurrency": "2.1.2"
  }
}