Scripting Language extensions via plugins

Is there any information available about how to build the plugin with LUA support into my game project’s Plugins, instead of rebuilding the entire engine with the WITH_LUA define set to true?

It appears as if it is designed in such a way that I really don’t need any of the WITH_LUA stuff and can subclass the existing plugins that are included with the engine to create my own version then add the code that is in the WITH_LUA blocks to my subclassed versions of what is in the engine to make it do the right thing. Is my assumption correct? I really don’t want to have to rebuild the whole engine, and would rather deliver the Lua support via a submodule into each and every projects plugin folder.

Are my assumptions correct? Any pointers or tips to lead me down this path would be appreciated. Never building a UI plugin from scratch is also compounding this process, but that’s my plight, not the creators.