Nesting Ember Applications and single-spa

Hi all–

I have been trying to create a POC to integrate Ember applications with single-spa (and single-spa-ember) and have run into some issues regarding multiple Ember applications being loaded onto the same page.

I am trying to accomplish something similar to this but with the following slightly-different application structure:

  1. There is a root-config project which registers the micro-frontend ember applications
  2. There is a parent Ember application which loads the root-config project, along with the child Ember micro-frontend in a SystemJS import map
  3. There is a child Ember application which is a micro-frontend and is registered by the root-config

Upon running the application, the parent Ember app successfully receives the root-config and Ember child app files from the servers. However, the child app does not get loaded on the DOM due to the following error:

Uncaught (in promise) Error: Assertion Failed: You cannot make a new Ember.Application using a root element that is a descendent of an existing Ember.Application

The problem here does not have to do with single-spa or single-spa-ember: all of that is working as expected. The problem is with nesting multiple Ember applications onto the same page in the DOM.

Is this possible, specifically without using Ember Engines? Is there any way to nest multiple Ember applications onto the same page?