Module support?

What sintakonte has written is a very good illustration.

1. IMO the first possibility is to be preferable, and I use it mostly.

2. The second possibility makes sense in very specific cases, generation of automatic email messages for example. I can identify two main disadvantages for ordinary cases:
- HTML is generated by the sub-controller, then it is returned to the main controller, then it is passed to the main view to be inserted somewhere there. This is waste of memory and performance;
- Code of the main controller is polluted with additional code, making it not clean for reading and in some cases future changes might need corrections within the main and the sub- controllers.

The second possibility I think is what people call "controller calls a controller", and they are right about criticizing it. But it does not mean that there is something wrong with HMVC - apply preferably the first possibility and code will be fine.