A "control character" (such as form feed) is kind of by definition not "text", but more importantly this was fixed for XML 1.1, which is like 14 years old at this point.
And
>You are encouraged to create or generate XML 1.0 documents if you do not need the new features in XML 1.1; XML Parsers are expected to understand both XML 1.0 and XML 1.1.