This reminded me of this link, which I've just posted to HN
https://partyfly.github.io/tokenizer-fairness-2026/
Already been using English to conserve tokens, and then translate the final result to other languages if necessary. I think this was already obvious to most international LLM users proficient in multiple languages.
I do use English for coding AIs. Most CS resources are in English so I thought that it should be far more efficient and accurate to use English. Some of my coworkers use our native language though.