I used this arcane incantation by @emanuele6:
< <(grep -hoP -e '\\u[A-Za-z0-9]{4}' ./*.json) grep -i -ve '\\u001b' \
| sort -u \
| while read -r; do
sed -i "s,\\$REPLY,$(eval "echo $'$REPLY'"),g" ./*.json
done
Plus some manual editing to re-align everything. Thanks! :)
Accentuated letters and other characters from the Unicode Block
"Latin-1 Supplement" were added; they weren't supported in the past.
Regarding the numpad: there was a `"", ` too much in the keymap, which
was shifting the keys when pressed (e.g. I would get a '9' instead of a '+')
