So I started to work on the Bash Bunny to be able to handle non-US keyboard layout attacks for ATTACKMODE HID.
To enable the SET_LANGUAGE option you need to add a [LanguageDescription].json under /root/tools/language.
I used the default "us.json" as a working template. (you wanna back it up and copy it and not work of the original file)
Here is an example of Japanese keyboard layout description file: (i.e.:ja.json , however you can make it ja_win.json for specific environments.)