There may be environments where special characters (non ASCII) will work, but there are also situations, where server operating systems, web server software, proxy servers, learning management systems, client operating systems, client browsers are not happy about special characters like german umlauts (ä,ü,ö,ß).
We are using page names in the menue object, so we can not easily change them to fit the needs of the sourrounding technology, because they are visible for and used by the learners.
The best way would be to provide an option to change the page name and file name separately.
An option to rewrite page names to better file names while publishing would also be a good choice (perhaps with the possibility to adapt the translation table).
The existing options only to use page titles OR page IDs are not enough.