LLMs work with tokens, not letters. So that's not going to work.

It might work in an agent system where it can make and execute code to solve problems.

By the way, why _do_ llms work with tokens and not letters? Is that some kind of optimization, or is there a more fundamental reason for it?

I actually would love to see the output of an LLM that used letters or syllables or phonemes. The output when it makes mistakes would be absolutely wild.