Lazily load routeless engine

route.js

import Route from '@ember/routing/route';
import { get, setProperties } from '@ember/object';
import { service } from 'ember-decorators/service';

export default class extends Route {
  @service assetLoader;

  engineName = 'image-editor';

  async beforeModel() {
    if (!this.router._engineIsLoaded(this.engineName)) {
      const assetLoader = get(this, 'assetLoader');
      await assetLoader.loadBundle(this.engineName);
      this.router._registerEngine(this.engineName);
    }
  }

  setupController(controller, model) {
    setProperties(controller, {
      engineName: this.engineName,
      imageUrl: get(model, 'url')
    });
  }
}