You're right. In some cases that's plenty, such as with the sentence "Mr. Jones was found XXXXXXXXXXXXXX of the crime." If you know it's likely either "guilty"

You're right. In some cases that's plenty, such as with the sentence "Mr. Jones was found XXXXXXXXXXXXXX of the crime." If you know it's likely either "guilty" or "not guilty," then the length (regardless of font) will automatically give away which of these two options it is since you can just 'bruteforce' the whole solution set of two options. No in-place redaction will work for a case like that, except possibly a longer one where the whole sentence is redacted and hopefully no one can guess what kind of sentence it was.