just a suggestion since most the coding is language file generation.
+ create a seperate plugin to make and update the language file generation
+ Main Plugin will stay cleaner

Thought about it a few times, main issue is, I don't think it would be approved (by umod) even if it was an optional addon.

Fair enough

There are easy-to-read regions that you can collapse so it's not really an issue much anyway. 

Splitting the lang files would be unnecessary. We are planning to have English in plugins by default though and additional available via download.