As various Japanese developers have discovered, you can fit quite a lot of distinct characters into 8x8 if your audience is familiar with them: https://japanese.stackexchange.com/questions/36423/is-this-8...

However I don't think even native developers with full Unicode language support tend to use Japanese/Chinese characters in variable names or keywords. There is the occasional hybrid registry key such as "令和_令_Reiwa_R" (which will allow the temporary replacement of the name of the Emperor in Windows dates when the current one dies).