I know Taiwanese abbreviate Instagram as IG. I have noticed that at least some people pronounce this G like 居 (jū), rather than any tone variant of ji. If I remember correctly, I think I have actually seen it written with this Chinese character.
However, this contradicts what the accepted answer to this question claims. I have also checked this Wikipedia article but 居 is not listed there, either. So I’m wondering if they use a different set of characters to represent the pronunciation of the English alphabet in Taiwan.
I would appreciate it if anyone could point me to a complete table.