I hope to hear more in the future! Do you envision any extension points to the way engines are implemented that could better enforce boundaries? In our engines

I hope to hear more in the future! Do you envision any extension points to the way engines are implemented that could better enforce boundaries? In our engines, there was nothing that referenced another engine's resources, leaving the main application to handle route mapping and ActiveRecord associations between app models and engine's models. I feel like the use-case for engines has long been around supporting framework like functionality (Devise, Spree, etc), but I wonder if there are changes to be made that better support modularization for large apps.