It is now completely integrated. The new system is more flexible, it adds support to include a layout from a plugin on a specific act, before or after the main include. For example I can with this new system, create a layout for the Mods DB plugin and include in the profile page, the user's mods without even needing to edit anything 

Will do the documentation later

Sounds good. I will give you the template for the documentation to make it all uniform.