The plugin supports unicoded URLs, no need in translit.
Regards,
Sardar
Sorry, but I can't provide translit rules for all languages. Today most part of the sites (check for example wikipedia.org) use Unicode URLs, and almost all browsers support it without any problem. Only old IE versions convert "/groups/группа-1 to/groups/%D0%B3%D1%80%D1%83%D0%BF%D0%BF%D0%B0-1". In IE9/10, FF, Chrome and Safari everything works fine.
If you need translit anyway I can add an event to slug generation function and you'll be able to implement rules you need in separate plugin.
Regards,
Sardar