Actually it's not all that trivial given the sheer amount of text.

That 'lang file' is pretty much what the 0.9.7 translator.php files were.
They were also horribly slow and bulky.
They also don't deal very well with 'constructed' text which a lot of the text in lotgd is.

We have a better system in development for 0.9.8.
However, you're free to make the attempt to convert 0.9.7 over to something like you envision.  let us know how it goes

I'm assuming you are asking when the next release is expected?

The answer is (as always): when it's ready.

It's not ready currently, and neither Eric nor I have had a lot of time to work on it recently.