What's the best way to create an engine for an engine in Rails?

Question

I am working with an engine in Rails and I'd like to extend its functionality with additional models and controllers in a modular format. My idea was to create an "engine for an engine." Is this the best approach? If so, how would you achieve this? If not, what would be a better approach?

Answer 1

What about creating an other Engine that you would mount in your main application in addition to the first one ?

CoreEngine
ExtendedCoreEngine

Are your additional models and controllers specific to the Engine and have nothing to do the any Rails application your engine is mounted in ?