http://www.quickandeasywebbuilder.com

Enjoying QnEWB 9 - and the new eCommerce options.

However, I would like to see an integration with OpenCart or Prestashop.

Is this possible somehow?

These solutions are not natively supported.
But you can add third party code via the HTML tools. This will require some HTML knowledge.
https://quickandeasywebbuilder.com/add_html.html

I assume he is looking for a more integrated solution. I actually think its a good idea because when working with the editor its difficult to just see HTML gray boxes.

These scripts need to be installed on the server, so it is not possible to integrate them directly into the software.

Here is an application for some inspiration maybe - they are a WYSIWYG editor and have the ability to make Prestashop and Opencart websites:

https://templatetoaster.com/opencart-theme-builder

They seem to have a way of doing it. That would be really cool to see the same ability within QnEWB

Sorry, but this is beyond the scope of this software.
QWB is not a template generator.