Very simple idea, worked for PT-BR to EN/JP pairs

Implemented this on two websites and it worked relatively well. Still some limitations if you have everything hardcoded in the theme files but for normal posts the process was pretty straightforward.

Would recommend adding more options for the switcher design as well as being clearer as how menus in different languages work. Also having to download the JSON file and then sending it to an AI to translate took a little bit longer than expected.