Can you LLM a custom language?

If token limit and accuracy are important, it seems English (or other spoken languages) are no optimal.

They're a butchered product of history and easy verbal noises.

A new custom language seems inevitable, that is concise, unambiguous, rooted in relation with custom words. Replacing common sentences with simple strings such as "Once upon a time..." to "a1"

Most likely alpha-numeric, to minimise tokens, and generate an order of magnitude increase in context window.

Followed by translation back to {language}

Is this possible? Anyone working on it?

(here to be educated)