When categories are used in some languages, accents are used occasionally.
It would be great to standardize the names or accents, that is, if the category was "über" create folder "uber", if "Français" create folder "francais"
I also have this problem when using Jekyll to my pt_BR blog.
Agree. Even without foreign languages, I just like to have my permalinks to be only lower case letters, digits and hypens, no spaces and no upper case letters. So not "Mr Hyde" but "mr-hyde"